One behind Rudolph's girls being spiteful (6)
I believe the answer is:
vixens
'one behind rudolph's girls being spiteful' is the definition.
I can't judge whether this defines the answer.
'one behind rudolph's girls being' is the wordplay.
I cannot really understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
'being' could be 'ens' (philosophical term for being or existence) and 'ens' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for vixens that I've seen is " Female foxes or spiteful women".)