Backed up by dad, this young creature is inactive (4)
I believe the answer is:
pupa
'this young creature is inactive' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'backed up by dad' is the wordplay.
'backed' is a reversal indicator.
'by' is a charade indicator (letters next to each other).
'dad' becomes 'pa' (pa can mean someone's father).
'up' back-to-front is 'pu'.
'pu'+'pa'='PUPA'
Can you help me to learn more?
(Other definitions for pupa that I've seen before include "Phase of insect life" , "developing creature" , "So peacock may have appeared" , "One is growing" , "A chrysalis as of butterfly" .)