I used one of these as the first encounter for a one shot I was running. One awakened tree vs. a monk, barbarian, fighter, and a wizard (all level 2). Never in my life have I rolled as well as I did that night.

Turn one: Max damage (not a crit) against the fighter grappling it. Fighter is down. Turn two: Attacks the fleshy wizard who decided walking up to it after shooting fire bolts at it was a good idea. Wizard is down. Turn three: Attacks monk, 'cause the barbarian hadn't hit it yet and didn't seem like a threat. Monk is down. Turn four: Wizard crit-ed back up, and was immediately killed (as in perma-dead) by tree (I rolled to see if it noticed him getting up, and it rolled a crit 20). Turn five: The fighter decides to accept death, and I allow the two dead party members to act as spirits. Turn six: The monk gets back up and the wizard's spirits successfully manipulates the tree (crit 20) into attacking an illusion of the one shot's finale boss spectating the whole fight. Turn Seven: The monk and barbarian try to kill it as it goes for the illusion (fails save to get focused on the fight again). Turn Eight: Barbarian finally kills the tree. (Turn numbers may be slightly off)

Many, many, many things went wrong with this fight on all accounts. I was rolling way to good, even when I (as DM) tried to "meh" roll the die in an attempt to roll low. The players were having terrible luck. The only attack the tree had dealt 3d6+4 damage (way to high for a small party of level 2 players). The party had no healers. So on, and so on...

But talking to the players afterwards, they still had fun. The two who lived where thrilled with the intense battle, the wizard was excited to use a new character idea they just thought of, and the fighter had fun in the (kinda) afterlife bit messing with the monk. I also learned a few things as a DM. Like for example...

NEVER FIGHT A TREE, YOU WILL DIE!

... and that even if the ending result is a failure, the fight can be still be one fun adventure... (man, that was cheesy)

That's amazing. Used a beefed up version of this in the Feywild. 7 level 3s fought one with double hit points and could Multiattack, but not against the same target twice.

I wish my Druid could Transport via Plants through this dude...

6 to tree

hats off, this is the most op cr2 ever

Be Druid. Create army of awakened trees, shrubs, cacti, weeds, etc.

”they call me the.. Pottomancer”

You think this is a story?

Don't even get me started...

It started nicely. A monk, wizard, sorcerer, rogue, and two clerics... all level 1. I planted a bean from Bag of Beans and a Treant popped out. We started kicking its butt then the DM was like hmmmm this is too easy and this Treant can make animate trees... Well she summoned two trees with the SAME STATS AS THE TREANT. Might I remind you we were level 1? So three Treants... hmmmm they each had over 120 HP and our max HP was 12 I think. The battle ended with EVERYONE except our rogue lying on the ground unconscious in the forest outside of the town (where I own a tavern). The treat scored like three hits and I think they were all on me. I technically should have died but the DM was like, "No you're not gonna die I messed up AAAAAHHHHH!!!!" So I DM a game and she plays in it... I think this is a great time for revenge... Oh and don't even get me started on the time I sent the ochre jellies at my players...

The spiritual leader of the Eldeen Reaches (essentially a druid nation in Eberron) is one of these. He’s also an archdruid.

"I am Groot"

If you lure some zombies near it and they fight, well you probably already know the joke I'm about to make, so I won't say it

NGL, took me a while to figure it out

I would love to pit awakened shrubs and these guys against some zombies 

Quote from BirdMonk >>

~ I planted a bean from Bag of Beans and a Treant popped out. We started kicking its butt then the DM was like hmmmm this is too easy and this Treant can make animate trees... Well she summoned two trees with the SAME STATS AS THE TREANT. Might I remind you we were level 1? So three Treants... hmmmm they each had over 120 HP and our max HP was 12 I think. ~

{Nods.} Mm-hm, mm-hm, this is how a Treant works... Turn 2 trees per day into Slam-happy psychopaths.

“The Tree has Awoken!”

that would be awesome why isn’t this possible?

My 6th level druid has a Woodland Staff, which can cast the spell awaken. he dig a hole towards the tower of the BBEG (who has a dragon) and for 4 days he awoke 4 trees around the tower to get ready for the big invasion. It's being over a week in the game now and the trees are still there waiting to be called for battle. Gotta love that False Appearance feat.

Lo iba a usar para mi campaña pero viendo los comentarios, mejor pongo otra cosa 

this needs Blindsight to function properly 

Quote from nombit >>

this needs Blindsight to function properly 

 That would mean it doesn't see, but detects creatures nearby through a sixth sense like animated armor. It's possible this can see regardless if it has eyes, and since the rules don't specify, but are consistent with awakened plants being able to see, we're left to assume they can. If they couldn't,it would say so, or they'd be immune to blindness or something. But DMs are always free to change this to fit their own idea of how it works.

I doubt it'd be worse to smash a tree with a maul than to burn it, it's hard as hell to burn a normal tree, let alone one that can defend itself. But I guess it is rare to find fire vulnerability and it fits the stereotype so... And wait, poison works fine?