Creature making a little bear mad -- I'll observe (9)
I believe the answer is:
armadillo
'creature' is the definition.
(armadillo is a kind of creature)
'a little bear mad i'll observe' is the wordplay.
'a little' indicates the answer is hidden within the clue (a little bit of the clue).
'ARMADILLO' is hidden within 'bear mad ill observe'.
'making' acts as a link.
(Other definitions for armadillo that I've seen before include "Burrowing mammal with a covering of bony plates" , "Dollar, ami for S American animal with bony plates" , "protected species" , "American insect-eater" , "Mammal covered with horny plates" .)