Ents should provide a place for a duck to build a nest where it would regen
slightly better. Thrikhrens could eat leaves of the ents, a leech could
parasite on ent sap, causing the ent some -hp, a skilled ranger could chop a
nice, big chunk of wood (-hp) from an ent and move to another room and build a
VERY NICE camp fire from it... etc. etc.