Ok, so i got an idea quite a bit ago for an idea of a mindflayer. I know the basic idea for mindflayers from Volo's guide to Monsters but for roleplaying once as a character instead of a NPC i was looking for a bit of help on creating one. 

My idea is a rogue mindflayer who broke away from the elder brain and decided to study humans instead of devouring them. I know Mindflayers need brains to consume so they don't.... D I E, but is there a way for a mindflayer to live without this substance or is it set in stone.

Really, they just need the psychic energy to survive. It is feasible for an ilithid to have found a way to skim psychic energy from folks similar to how Flumphs do it. 

Thats interesting, do you, if by any chance, has writing for this or anything i could browse through?

Quote from WendigoOfLore >>

Ok, so i got an idea quite a bit ago for an idea of a mindflayer. I know the basic idea for mindflayers from Volo's guide to Monsters but for roleplaying once as a character instead of a NPC i was looking for a bit of help on creating one. 

My idea is a rogue mindflayer who broke away from the elder brain and decided to study humans instead of devouring them. I know Mindflayers need brains to consume so they don't.... D I E, but is there a way for a mindflayer to live without this substance or is it set in stone.

 Weeellll, they never said it has to be humanoid brains, i think, since people eat the brains of animals in some places anyways

Quote from WendigoOfLore >>

Thats interesting, do you, if by any chance, has writing for this or anything i could browse through?

 Maybe?

Off the top of my head, here on D&D Beyond, there is Van Richten's Guide to Ravenloft, that details other Dread Domains like Bluetspur, where an Elder Brain developed psychic Vampiric Mind Flayers to go out and drain psychic energy to feed like mosquitoes and then it just skimmed off them. Those have a Drink Sapience ability that does psychic damage and gains health. It is not impossible for a PC ilithid to have maybe a slightly gentler version of this. 

I would suggest either a class ability or a spell.  Create Food and Water is a 3rd level spell, I see no reason for an illithid not to develop a similar psychic ability or spell that feeds itself for a day.

Alternatively, I can see a class ability or feat do something similar.   In particular, I can see a Druid using Wildshape to eat.  If you get consume sufficient fuel for the animal, you should keep the nutrients even after you return to your original form.  

The Illithid should be able to sustain themselves using that method.

Quote from WendigoOfLore >>

Ok, so i got an idea quite a bit ago for an idea of a mindflayer. I know the basic idea for mindflayers from Volo's guide to Monsters but for roleplaying once as a character instead of a NPC i was looking for a bit of help on creating one. 

My idea is a rogue mindflayer who broke away from the elder brain and decided to study humans instead of devouring them. I know Mindflayers need brains to consume so they don't.... D I E, but is there a way for a mindflayer to live without this substance or is it set in stone.

You're going to have to homebrew this, of course, so the question is, how deeply into homebrew do you want to go?5E RAW, from the Mind Flayer entry:  Illithids subsist on the brains of humanoids. The brains provide enzymes, hormones, and psychic energy necessary for their survival. An illithid healthy from a brain-rich diet secretes a thin glaze of mucus that coats its mauve skin. An illithid experiences euphoria as it devours the brain of a humanoid, along with its memories, personality, and innermost fears. Mind flayers will sometimes harvest a brain rather than devour it, using it as part of some alien experiment or transforming it into an intellect devourer.  This means you will starve to death without humanoid brains to eat, but we don't know anything more about your dietary needs.  If we use the generic starvation rules, you need a pound of humanoid brain matter every 4+your con modifier days to avoid starvation; this pound is set by your size and is independent of the brain matter's other attributes.  An average human brain weighs about 3 pounds, but the above text implies you dare not dry out the brain matter lest you miss out on necessary sustenance, and you don't have refigeration, so you probably can't make a brain last you beyond the day you extract it.  That would mean you need to eat 1 fresh brain every 4+Con modifier days, period.

1. You could homebrew being able to eat like a whale or seasonal bear: you can store excess nutrients and automatically metabolize them.  This would violate the RAW on starvation, but it's not like you have a set of racials for a mind flayer to work from, so it could easily be added on as a ribbon.  That would mean every 4 + Con modifier days you need to eat a brain or starve, but eating said brain feeds you for 3 days, so if you're stringing it out and getting a regular supply, you only need a brain every 6 + Con modifier days.
2. You could homebrew some arcanotech (which Mind Flayers canonically do have, we just don't have a lot of detail on what they can and can't do with it) to give you a jar of brain preservation, which by definition prevents brains inside it from rotting, even preserving the psychic energy inside.  That would let you use the extra pounds on non-sequential days, letting you consume 1 brain every 3*(4+Con modifier) days.
3. No-longer-canon RAW from 3.5E in the Lords of Madness book (page 62) states that you can basically think of the Illithid GI tract as being very similar to a human's except that an Illithid's brain is much more deeply wired into it (and the rest of its anatomy) - you can think of their entire digestive system as being self-aware because the Illithid is self-aware, and they can take manual control of their digestion.  This suggests that not only is item 1 how Illithids are intended to work, since they can control their equivalent of fat storage, but they can do item 2 without needing a jar at all, just having it as a racial ability.
4. As in 3, the same book on pages 67-68 explicitly spells out that Illithids have these jars and provides rules for them; these jars are explicitly sometimes used to store food for long journeys, as opposed to their default use of storing a dead Illithid's brain until it can be fed to its Elder Brain.
   1. Page 68 of the same book covers their iconic suit, which so far as I know has no 5E RAW.  In 3.5E it made you immune to Con saves against environmental temperature (so hot or cold air or water, usually, no actual damage resistance), despite having fluff about it retaining moisture; you could certainly justify bringing it into 5E and adding the ability to let you only need as much water as a Tiny creature (1/4 gallon) a day to get by.  This won't help you with your brain problem but is possibly related to your overall survival concerns.
5. Goodberry berries explicitly feed any creature for a day, which means you (or any Mind Flayer) can eat them and avoid starvation.  This doesn't mean you'll stop feeling hungry and the goodberry probably won't provide brain euphoria, but you won't starve.
6. Create Food and Water has limits on quantity and is explicitly "nourishing" even for exotic consumers (the spell discusses humanoids or "steeds" in its quantity limits, but even if your DM thinks this controls the nature of the food, a "steed" can be an aberration).  You can use this to get by and you should feel full, even if "bland" is translated to "not euphoric".
7. No-one really knows if Heroes' Feast can genuinely feed you, but I would expect most DMs to rule that it can.  Regardless, because the food explicitly tastes good, you should be able to use it for your euphoria fix.

Quote from quindraco >>

Quote from WendigoOfLore >>

Ok, so i got an idea quite a bit ago for an idea of a mindflayer. I know the basic idea for mindflayers from Volo's guide to Monsters but for roleplaying once as a character instead of a NPC i was looking for a bit of help on creating one. 

My idea is a rogue mindflayer who broke away from the elder brain and decided to study humans instead of devouring them. I know Mindflayers need brains to consume so they don't.... D I E, but is there a way for a mindflayer to live without this substance or is it set in stone.

You're going to have to homebrew this, of course, so the question is, how deeply into homebrew do you want to go?5E RAW, from the Mind Flayer entry:  Illithids subsist on the brains of humanoids. The brains provide enzymes, hormones, and psychic energy necessary for their survival. An illithid healthy from a brain-rich diet secretes a thin glaze of mucus that coats its mauve skin. An illithid experiences euphoria as it devours the brain of a humanoid, along with its memories, personality, and innermost fears. Mind flayers will sometimes harvest a brain rather than devour it, using it as part of some alien experiment or transforming it into an intellect devourer.  This means you will starve to death without humanoid brains to eat, but we don't know anything more about your dietary needs.  If we use the generic starvation rules, you need a pound of humanoid brain matter every 4+your con modifier days to avoid starvation; this pound is set by your size and is independent of the brain matter's other attributes.  An average human brain weighs about 3 pounds, but the above text implies you dare not dry out the brain matter lest you miss out on necessary sustenance, and you don't have refigeration, so you probably can't make a brain last you beyond the day you extract it.  That would mean you need to eat 1 fresh brain every 4+Con modifier days, period.

1. You could homebrew being able to eat like a whale or seasonal bear: you can store excess nutrients and automatically metabolize them.  This would violate the RAW on starvation, but it's not like you have a set of racials for a mind flayer to work from, so it could easily be added on as a ribbon.  That would mean every 4 + Con modifier days you need to eat a brain or starve, but eating said brain feeds you for 3 days, so if you're stringing it out and getting a regular supply, you only need a brain every 6 + Con modifier days.
2. You could homebrew some arcanotech (which Mind Flayers canonically do have, we just don't have a lot of detail on what they can and can't do with it) to give you a jar of brain preservation, which by definition prevents brains inside it from rotting, even preserving the psychic energy inside.  That would let you use the extra pounds on non-sequential days, letting you consume 1 brain every 3*(4+Con modifier) days.
3. No-longer-canon RAW from 3.5E in the Lords of Madness book (page 62) states that you can basically think of the Illithid GI tract as being very similar to a human's except that an Illithid's brain is much more deeply wired into it (and the rest of its anatomy) - you can think of their entire digestive system as being self-aware because the Illithid is self-aware, and they can take manual control of their digestion.  This suggests that not only is item 1 how Illithids are intended to work, since they can control their equivalent of fat storage, but they can do item 2 without needing a jar at all, just having it as a racial ability.
4. As in 3, the same book on pages 67-68 explicitly spells out that Illithids have these jars and provides rules for them; these jars are explicitly sometimes used to store food for long journeys, as opposed to their default use of storing a dead Illithid's brain until it can be fed to its Elder Brain.
   1. Page 68 of the same book covers their iconic suit, which so far as I know has no 5E RAW.  In 3.5E it made you immune to Con saves against environmental temperature (so hot or cold air or water, usually, no actual damage resistance), despite having fluff about it retaining moisture; you could certainly justify bringing it into 5E and adding the ability to let you only need as much water as a Tiny creature (1/4 gallon) a day to get by.  This won't help you with your brain problem but is possibly related to your overall survival concerns.
5. Goodberry berries explicitly feed any creature for a day, which means you (or any Mind Flayer) can eat them and avoid starvation.  This doesn't mean you'll stop feeling hungry and the goodberry probably won't provide brain euphoria, but you won't starve.
6. Create Food and Water has limits on quantity and is explicitly "nourishing" even for exotic consumers (the spell discusses humanoids or "steeds" in its quantity limits, but even if your DM thinks this controls the nature of the food, a "steed" can be an aberration).  You can use this to get by and you should feel full, even if "bland" is translated to "not euphoric".
7. No-one really knows if Heroes' Feast can genuinely feed you, but I would expect most DMs to rule that it can.  Regardless, because the food explicitly tastes good, you should be able to use it for your euphoria fix.

 

 Thank you :D. This is extremely helpful 

I do not think Create Food and Water will work, it says Humanoid, not creature.

But Goodberry and Heroes Feast say Creature.  Both are Druid spells.

If I were the DM, I would say that playing a Druid makes a ton of sense for you.  It not only gives you Goodberry, Wild Shape, and Heroes' Feast to feed you, but it also makes a lot of sense for why the Illithid decides to go their equivalent of Vegan.

Hm, there should be a slightly insulting word that means refusal to be eat intelligent beings that the other Mind Flayers call you.  How about "Mouth Eater" because you do not use your tentacles?  Or do you prefer "Teeth User"?  

Quote from Mog_Dracov >>

Hm, there should be a slightly insulting word that means refusal to be eat intelligent beings that the other Mind Flayers call you.  How about "Mouth Eater" because you do not use your tentacles?  Or do you prefer "Teeth User"?  

 

 I believe they'd typically go with "kill the heretic!"

I;m a bit late to this one but this is how I;d go for it:

Race: Any you like but for purposes of this I'm going for Githzerai because of their racial spellcasting, this isn't to say you are a Githzerai its just the one that gives the best flavour abilities.

Backstory: you've been impregnated by an Illithid Tadpole which has changed your appearance to that of a mindflayer but for some reason has not connected you to the Elder Brain nor fully awakened the Mind Flayer innate psionic abilities. You cans till eat and drink as normal but can always go down the normal Illithid diet route as and when required.

Background: Any you like.

Starting Class: Rogue going for 4 lvls and taking Soulknife, taking proficency and expertise in Inisght and a charisma based skill. These along with Cunning Action can be flavoured as minor empathic abilities allowing you to more easily influence, read and evade those around you. Rather than summon Psychic blades these will be psychically infused attacks with your tentacles and if you decide to throw them then you are unleashing a small psychic blast at the target but this does require your DM to agree that for the your tentacles still count as a weapon attack when using the Soulknife Psychic blades ability so you can add Sneak Attack to it to represent a particularly powerful blast of energy or infused tentacle strike.

Multiclass: Bard going for College of Whispers taking psychic based spells with damaging spells being variants of the Mindflayer Psychic Blast and gives you the added bonus of being able to expend inspiration dice as additional psychic damage.

So thats the basic idea.

Could illithids to farm hydras to eat the brains from their heads? And brains by trolls, or any "transgenic" variant, for example half-trolls?

Illithids are too powerful to be level 1 PCs. You had to create a nerfed homebred version. Maybe the product of a experiment created by illithids to send spies among the other races. Then here the diet of brains wouldn't be neccesary because it would help for a better infiltration. The thoon cult also could create something like this.