Hangman Tree
The Hangman Tree is a carnivorous plant in Advanced Dungeons & Dragons, since the second Monster Manual, an arboreal garden of evil.
The tree looks like an oak and indeed can share a forest with such. Its (few) branches have few leaves, but dangle vines like nooses. The lower trunk has an apparent scar actually an... anus.
These vines aren't usually precise enough to strangle the victim. Instead after 4 rounds the vine will drag the victim into its maw. Each tree has 6-9 nooses but can control only three at once. Each noose can lift up to a thousand pounds and can take 13-20 points of damage.
In the tree's gullet, which fits about three men at once, the victim(s) have difficulty getting out due to in-facing spines around the maw. The tree's stomach is acidic, for 3-12 points per round. After digestion, the remains get pooped out the scar.
Its range is subtropical-to-temperate. In the warmer seasons its roots are shallow, if that; it can move at "a few feet per day" or two feet per hour (the MM2 is inconsistent here), although saplings can move six feet per hour. Some photosynthesis happens; darkness (natural or not) weakens it by "half efficiency". In winters it goes into dormancy, not moving, instead putting down taproots.
We do insist upon the singular; such don't cluster in "hangman forests". The tree may exude a "hallucinatory perfume" to 30-80' in case someone sees this tree as out-of-place. It has some rudimentary ("Low") intelligence and can talk in Common.
The tree didn't quite make third-edition so the Tome of Horrors did the needful. Its most recent appearance was in Dungeon Magazine #195 for Dungeons & Dragons 4th Edition and Nentir Vale.