Creature in puma's lair disturbed (9)
I believe the answer is:
marsupial
'creature' is the definition.
(marsupial is a kind of creature)
'puma's lair disturbed' is the wordplay.
'disturbed' indicates anagramming the letters (the order of letters is disturbed).
'pumas'+'lair'='pumaslair'
'pumaslair' with letters rearranged gives 'MARSUPIAL'.
'in' is the link.
(Other definitions for marsupial that I've seen before include "eg Wallaby" , "An animal like the kangaroo, female with a pouch for carrying young" , "Sort of animal" , "Kangaroo, for example" , "Mammal that carries its young in a pouch" .)