Piggy is holding up another animal (9)
I believe the answer is:
porcupine
'another animal' is the definition.
'porcupine' can be an answer for 'animal' (porcupine is a kind of animal). I am unsure of the 'another' bit.
'piggy is holding up' is the wordplay.
'piggy' becomes 'porcine' (synonyms).
'is holding' indicates putting letters inside.
'porcine' going around 'up' is 'PORCUPINE'.
Can you help me to learn more?
(Other definitions for porcupine that I've seen before include "Spiny animal" , "Rodent with sharp bristles" , "Recoup pin from its bristles" , "Spiny creature" , "Rodent with sharp black-and-white spikes" .)