A friend had an idea for a candyland dnd adventure.  My first thought is faerie shenanigans.  Is Count Licorice really bad guy?  Does Gloopy just want to make friends(accidentally smother them)?  Is Frostine planning to cover the world in icing?

Playing into fae traits such as food being mildly dangerous and fae bearing gifts sounds like it could work quite well in this setting.  Maybe the children have some sort of destiny and everyone wants to use this to their own advantage.

I only have vague ideas at the moment, haven't really looked at what stat blocks I might use for these creatures.  Anyone have some hilarious and probably dark thoughts on what is really going on in Candyland?

A useful resource is probably The Legend of the Lost Candy Castle (p4-5 on that link). Also the Candy Land wiki.

I might steal a beat from the dresden series, and have the bad guys (whichever group that is) be the militaristic violent group, but also have them keeping something far worse at bay.  Maybe an incursion of outsiders attempting to create a beach head of sorts into the fey wild.  They seem like the worst but they are the ones holding the line and protecting everything.  

Perhaps fairy wings are being crushed into a fine powder to create a strange sugar, which manifests candies and candy monsters. If the players are high level, you could introduce a "Hard-Candy Golem", which is just a reword of the stone golem monster statblock (https://www.dndbeyond.com/monsters/17025-stone-golem).
Or a large "gummy bear", you can already see where this is going; use the bear or owlbear monster statblocks (depending on the players' levels of course) and send a couple of them in to fight! I reckon it would be fun if they were either relentless killers, or could be tamed by the players!
There are a lot of monsters you can simply rename into "candy" counterparts, by changing the statistics at your own choice (perhaps because of the sugary capabilities it is required for the PCs to have magical weapons in order to deal any damage to them!)
The idea of a candyland in the Fey Wild is awesome! And even more awesome with some darker aspects.
Good luck on your campaign!

I love the 'Rock Candy Golem' I have been writing out little brief bits for all the named characters in the Candyland universe, and 2-3 monster entries I could Reskin for the characters.

Like Gloppy is either a shambling mound, or a dragonblood slime (also considered Oblex but that's a little extra).

The King may have gotten into something dangerous before him and the castle disappeared.  Frostine is preparing some massive spell, that has her daughter Princess Lolly worried.  Frostine and Lolly may end up being a Winter and Spring Eladrin respectively.  Also considering a Bheur Hag for Frostine and a couple other Hag types for Gramma (or Nana) Nutt and Gramma Gooey.  And yes I am using characters from every iteration of candyland.  

The Lord liquorice is preparing his armies, for... something.  Mr Mint has been in the Peppermint Forest on some mission from the king and refuses to help looks for the missing King.  Nana Nutt wants to find the fabled candyland children to help them save (and hopefully not destroy) the Realm.  Gotta figure out the Duke of Swirl, and Duchess E Claire, I think they are status grabbers and the Duke was recently engaged to Lolly.

Many creatures could be given the mimics adhesive trait in order to make them feel gummy and sticky. 

Solid idea.

Quote from HeroZero >>

Nana Nutt wants to find the fabled candyland children to help them save (and hopefully not destroy) the Realm. 

 What if your players are (or seem to be) the candy land children? When they're transported to the fey wild, they're turned into 9-13 yo. versions of themselves. Have your players describe what the 9-13 yo. versions look like. Some NPCs treat them as children, some treat the as gods because they're "The Children", some don't care. 

Oh my, I had originally just figured any mortal seems like a child to the fey.  Buy that, is so much funnier to me.  Some are probably just so tired of children.

I could even have another set of children that have come through and might be the prophecied group...  might be a bit much.

King Kandy - The Imperial Head Bonbon and Grand Jujube of Candyland has gone missing (along with his castle).  Lord Liquorice has been implicated in this 'vanishing'.  Queen Frostine and Princess Lolly have been searching for the King, because without his presence Candyland is becoming diminished and could disappear if nothing is done.
     King Kandy may have been investigating something serious before the Vanishing.  Stranger still some residents do not remember the existence of the Candy Castle at all.  Rumors circulate that his inquiries were into strange beings and creatures that were found at the edges of his realm.  Other rumors say he was into something more sinister with his investigations and experiments.  Riverine Zorak Lightdrinker Exethanter (these are some creature blocks i am considering, they will be fluffed out and reskinned.  King Kandy is either full on diving into some strange power or is being controlled/corrupted by it, which is yet to be determined.  Might even change based on what the players think is going on.

Queen Frostine - The wife of King Kandy has been tirelessly searching for her missing husband and their disappeared castle after the Vanishing. Her and Princess Lolly heavily suspect Lord Liquorice is behind all this but have been unable to prove anything.  The Queen has been advised by Nana Nutt, that there is a prophecy that a group of children will arrive, they will bring back what was lost and save the realm from a great evil.
     Frostine has recently retreated to her summer castle in the Ice Cream Sea where storm clouds have been brewing.  From what little information has come out of the Ice Cream Float, it seems that the Queen was brought some information from an unknown messenger.  She then retreated to her personal wing where she is preparing some kind of spell.  She has told her retainers that it will save the kingdom, but will it? Winter Eladrin Bheur Hag Auril (Second Form)

Lord Liquorice - The Lord has been an outspoken critic of the King and Queen.  With the Vanishing many believe him to be involved, he denies all claims that he is trying to take over the kingdom.  The Lord had been consistently asking for increased funding and troops to defend the borders of their realm, and has been routinely turned down.  With the Vanishing he has stopped taking any visitors instead keeping council in his war room consulting his advisors.  To the outside he appears to be preparing for an all out war.
     After repeated messengers were sent to Queen Frostine, and none returned, Liquorice has retreated inward.  He has maintained some communication with Princess Lolly through the Royal Messengers.  None know what is contained in these communiques, but the Tea is that he has been courting the Princess, or the more sinister rumor is they were both involved in the Vanishing.  He gathers his allies Buzzy, Crocket, and Spidora to prepare for the next step of his plans.  Chain Devil Horned Devil Smiler the Defiler

Princess Lolly - Her father missing, her mother is preparing a mysterious spell, her arranged marriage to Duke of Swirl has fallen apart.  Everything is going pretty poorly.  She had to call off her marriage to the Duke because he wanted to be declared king immediately with the Vanishing, to in his words "Show that Candyland is still secure and that there is nothing to worry about".  On top of that messages to Lord Liquorice have been strained and cryptic offering very little information.  He is hiding something important but she cannot tell exactly what.
     Her mother seems to be losing her mind with grief, and whatever spell she is brewing is nothing but bad news.  The Duke is still pretending that the engagement is still on, and has been using his position to be a nuisance.  Her hopes all rely on getting Mr. Mint, Duchess E. Claire, and Jolly Gumdrop to work with her to protect the kingdom from enemies foreign, and domestic.  There is unrest brewing in Candyland, and something is coming.  Spring Eladrin Deva Reigar

That is some of the major players currently involved.  Likely Lord Liquorice knows exactly what caused the vanishing, but the why may be more important by far.  At this point I am still uncertain what kind of level I will be starting players at so I have been trying to pick a variety of CR stat blocks for each character for if/when they have to be fought I can use something appropriate for the encounter.  The next set will be Mr. Mint, Gloppy, Plumpy, Jolly Gumdrop, and Nana Nutt.

Mr. Mint - The leader of the Royal Minted Police was away from the castle on a mission in the Peppermint Forest when the Vanishing occured.  When word reached his unit he refused to leave the forest, saying it was on orders from the king.  His unit and a contingent of Snow Beavers have been patrolling the area ever since then.  He has refused all summons from the royal family to help with the search for the king.  Although he sent one single message to Lord Liquorice for unknown reasons.
     Strange stories have been coming from the area around the Peppermint Forest.  Odd music, strange grunting, and the occasional sounds of combat can be heard on calm nights.  Some even say that parts of the Peppermint Forest have gotten twisted in some way.  With all the other problems in the Kingdom no one has had the time to the goings on in the forest.  Yuan-ti Pit Master Nimblewright + Battleforce Angel Smiler the Defiler and for the Snow Beavers Dire Wolf

Gloppy - Even with everything going on Gloppy continues to guard the Molasses Swamp.  He really wants to make friends, but only intruders ever seem to come to visit.  Maybe Gramma Gooey will make him some new friends. Dragonblood Ooze Plasmoid Boss Shambling Mound

Plumpy - The last of the Plumpa Trolls is the care taker of the Gingerbread Plum Trees.  Mama Gingertree acts as his guardian.  He is the watcher at the entrance to Candyland eliminating any threats to the Gingerbread Plum Orchard.  Aside from his allegiance to Mama Gingertree, little is known of his motivations.  He is said to be an excellent tracker and will doing anything Mama Gingertree asks of him, even if he has picked up a bit of stress eating after the Vanishing.  Verbeeg Longstrider Venom Troll Four-Armed Troll

Jolly Gumdrop - Foreman of the Gumdrop Mountain Mine they work with their fellows to harvest one of the primary exports of Candyland.  Ever since the Vanishing, the quality of the Gumdrops has been dropping daily.  Their color seems to be leeching away with no end in sight, and who wants white gumdrops.
     The miners have been going deeper in the mines to find untainted gumdrop deposits.  But as they have gone deeper there have been disappearances, and the workers are afraid to continue looking for deeper veins.  On top of all these troubles Lord Liquorice has been demanding more resources for his 'protection force', and the Duke of Swirl has also been requesting money for the royal family to fund the search for the king.  Xardorok Sunblight Duergar Warlord

Nana Nutt - Nana Nutt live alone in the Peanut Brittle House commonly referred to as Nana's Nutt House far from prying eyes.  Somewhat of a recluse she has a congenial nature, with her Picnic Basket Dog Bazz being her only companion.  When the Vanishing happened Nana went through all of her gathered prophecies and found one referencing the current events.  "When Bonbon disappears, the children will arrive, The will find that which was lost, though foes would stop them, their actions can bring salvation".  This she sent to Queen Frostine, but she left out the final line to the prophecy, "Their arrival brings a Doom to Candyland".
     She hopes to meet the children and help them to bring salvation, but fears how others might react to the final line.  She plans to send her faithful companion Bazz to find them and help them, and destroy them if absolutely necessary.  Bazz is such a faithful, and loyal creature.  It would be a shame if he has to have their death on his paws.  Dusk Hag Astral Elf Aristocrat and for Bazz Behir Liondrake Canoloth

Someone offhand suggested the 'enemy' being from Ravnica, and now I am seriously considering it.  Originally I was going with elder God, alien horror, encroaching on their plane.  But the guilds of Ravnica taking an interest outside of their native plane could be interesting.  Different guilds would be attempting to take over different areas, or exerting influence.  Each would would be using different tactics in their attempt to control.  I don't think I would use all 10, of them but was considering a group of 5.  Now I am deliberating whether this will jive well. 

Duchess E. Claire - Her family was finally going to be joined with the Royal family, before the Vanishing ruined her plans.  Her son the Duke of Swirl should be the new king and now of all times Lolly wants to cancel the engagement.  Where is Frostine to talk Her out of this foolishness?  Lounging in her summer home not even helping in the search for her husband.
     No time to worry about all that, instead we must ensure that the good Duke of Swirl is seen taking control of the situation.  He must be the stability for the realm when the royals are nowhere to be seen.  If we can't have a wedding and do this the peaceful way, then perhaps a coup is in order.  Her son may be an idiot but he has a forceful personality, so it's time to put it to good use.  For the good of the kingdom of course.  Green Hag Night Hag Yalaga Maladwyn

Duke of Swirl - How dare the princess break off the engagement after everything he is doing for the kingdom during this time of tragedy.  Our mothers will sort this all out, and besides I found the Candyland Children.  I will be the one to save us all.  I just need some more funds from that idiot Jolly and to get the Royal Minted Police in line to do it.  Not even Liquorice can stop me then.
     Once I have solidified my hold, Lolly will be forced to take me back one way or another.  All this talk of strange beings is just a smokescreen for Lord Liquorice to take over.  His lies cannot continue, the Children will see to him being exposed for the tyrant he is.  On top of that some are saying there is another group of children pretending to be the chosen ones.  They will have to be crushed of course, for being charlatans attempting to undermine my authority.  They were probably sent by Liquorice, thrice damn him.  Cambion Oni Radiant Idol  (Note: I think they will have to deal with the Duke as a repeat encounter, Radiant Idol would be his resurrection after other defeats/escapes)

Mama Gingertree - The gatekeeper of Candyland that decides who is meant to be in Candyland, and who is not.  If Mama decides you don't belong you will not leave the orchard alive.  With her caretaker Plumpy and favorite child Jib, she has guarded the entrance for centuries.  She seems very gentle, but will change abruptly if offended in any way.  Rallying the orchard to remove the riff raff when the feeling takes her.  Even after allowing traveller's through she keeps an eye on them through Jib and Plumpy.
     Everybody trusts Jib because he is a kind hearted soul and seems so harmless.  Even if they don't trust him, Plumpy can track them from afar by following the smell of the gingerbread plums.  Mama however has been feeling off lately since the last group of brats came through.  Something must be wrong somewhere in the orchard.  Turlang Yggdrasti Tree Blight

Jib - Jib is everyone's favorite gingerbread boy.  He is kind and caring, and he always obeys his Mama.  Whatever Mama wants he will do it for her, he loves her so-so much.  He loves to tell Mama all about what his friends do, she loves Jib's stories.  Mama does get angry sometimes but she would never hurt Jib.  He looks forward to exploring the kingdom and telling Mama all about his adventures.
     Plumpy told him that these children might be imposters since the other children came through earlier.  They don't seem like bad kids, but Plumpy is his friend.  I bet that I can prove they are the children of the prophecy.  He will make sure not a single thing is left out of his stories, every little detail.  Certainly that is the best way to help everyone!  Wood Woad Flesh Golem Metallic Peacekeeper

Anyone have some funny ideas for names of candy creatures I could flesh out. I got Rock Candy Golem, Pop-rocks Pixies, Soda Sirens, alliteration not required.

I am working on a Fae campaign design now that my idea came from the Robin Williams film "What Dreams May Come". The Archfae is an artist, painter and the realm is his painting. As you walk thorough the realm your foot prints leave paint steps. The Artist has duel personalities and the painting changes with his wild mood shifts from dark and dagerous to a bealtiful, friendly world. 

This Candyland idea is genious! 

Oooo that sounds so splendid, finding beauty in the seemingly darkest areas.  Danger arising from something that seems so peaceful and placid.  A pleasant stroll through a wonderful rose garden changing into something more sinister, like a twisted hedgemaze filled with unseen dangers.  

Also potentially unpacking some traumas of an archfey sounds like a dangerous proposition.

Can I ask for ideas for mundane creatures or things that have been candyified.  Example is cottoncandy sheep.  Maybe even some of people's favorite candies, especially if they are "classics".  But anything from Turkish delight, to twizzlers is ok.  Trying to get at least some kernels to work with.  Candycorn is a little too easy.

Quote from HeroZero >>

Can I ask for ideas for mundane creatures or things that have been candyified.

Animal Crackers, Chocolate Bunnies, Gummi bears, Gummi worms, and Marshmallow Peeps are obvious candidates.

Something I was thinking about is Elementals of various flavors,can be piles of some small candy.  Electric Elemental would be Shock Tarts, and M&Ms or reeses pieces could form an earth elemental. 
     Swedish Fish, Pixie Stix,

I am now picturing a horde of chocolate bunnies attacking, I could probably use Harengon or similar.  As for Gummi worms, well lets not open that can of worms.  Purple worms, you got the little baby version at CR 2, and then suddenly the DUNE GUMMI WORM BREACHES from the ground like a boss.   Thank you again, it is amazing how just a couple ideas can set off a cascade.

Pop rock elementals.