Don’t say I didn’t warn you but this is going to smack some one up really badly when it unwinds!
In the Monster Manual we had Treants, in MERP they were Ents and Active Trees. If you are just coming to Rolemaster then Creatures & Treasures (Page 51) gives you three varieties to play with, the Awakened Tree, Slowroots and Treeherds being 5th, 10th and 20th level respectively.
Your Awakened Tree is the the classic horror moving dark forest that the innocent fool wanders into before disappearing never to be seen again while everyone in the audience is thinking “Why do they always go into the forest in the middle of the night all alone when people are disappearing?” (If you know what I mean.)
Your Slowroots and Treeherds are the more ‘goodly’ variants and the Rolemaster equivalents of Tolkien Ents as seen in the Lord of the Rings.
I am pretty sure the tree in the photo above is completely natural and the twisting just a turn of fate (groan!) and that I didn’t catch it about the beat the hell out of me. If that is true then how would a party of adventurers ever be able to tell when they walk into an ambush of this kind?