Animal concealed in red bag (6)
I believe the answer is:
badger
'animal' is the definition.
(I've seen this before)
'concealed in red bag' is the wordplay.
'concealed in' is an anagram indicator.
'red'+'bag'='redbag'
'redbag' with letters rearranged gives 'BADGER'.
(Other definitions for badger that I've seen before include "Pester -- nocturnal mammal" , "Pester the burrowing animal" , "Animal hunted by stocky dog" , "Disturb" , "Burrowing carnivore" .)