Initially had desire over Australian scavenger (5)
I believe the answer is:
hyena
'scavenger' is the definition.
(animal which scavenges)
'initially had desire over australian' is the wordplay.
'initially' suggests taking the first letters.
'desire' becomes 'yen' (yen can mean a longing or desire).
'over' means one lot of letters go next to another.
'australian' becomes 'A' (common abbreviation).
The initial letter of 'had' is 'h'.
'h'+'yen'+'a'='HYENA'
(Other definitions for hyena that I've seen before include "Beast" , "Creature" , "Dog-like animal with howl like laughter" , "Carrion-feeding carnivore" , "Wolf-like animal with cry like laughter" .)