Animal's popular tamer panicked, trapped by cage (4,6)
I believe the answer is:
pine marten
'animal's' is the definition.
(I've seen this before)
'popular tamer panicked trapped by cage' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'panicked' indicates an anagram.
'trapped by' means one lot of letters goes inside another.
'cage' becomes 'pen' (I've seen this before).
'tamer' with letters rearranged gives 'emart'.
'in'+'emart'='inemart'
'inemart' inserted into 'pen' is 'PINE MARTEN'.
(Other definitions for pine marten that I've seen before include "furry critter" , "Animal" .)