Abominable snowman (4)
'abominable snowman' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for yeti that I've seen before include "hirsute specimen" , "He's never had a successful Catcher" , "Mythical Tibetan beast" , "creature awaiting discovery?" , "whose existence is unconfirmed" .)
(Other definitions for bigfoot that I've seen before include "Supposed American ape" , "Supposed NW US ape-like creature" , "Fabled hairy primate" , "Supposed ape of northwest US" , "American 'apeman'" .)