Trevenant

Trevenant is the Elder Tree Pokémon, a Grass/Ghost-type that resembles a gnarled, ancient tree animated by a ghostly presence, with a single glowing red eye and root-like legs. Using the small roots extending from its feet, it can connect to and command other trees in the forest, effectively acting as a guardian of the woodland. It is said to be kind to Pokémon and others who treat the forest well, but it will trap and frighten those who harm the trees, sometimes ensnaring intruders so they cannot leave. Trevenant evolves from Phantump, a stump-like Ghost Pokémon born from spirits dwelling in tree stumps.

The Japanese name オーロット (Ōrotto) is generally understood to combine 大 (ō, 'big/great') with elements evoking 'old' and the English word 'rot' or 'root,' fitting its nature as an aged, decaying tree spirit; it may also echo 'all rot.' The English name 'Trevenant' blends 'tree' with 'revenant,' a term for a ghost or reanimated being that returns from the dead, reflecting its Grass/Ghost typing as a haunted tree.