Fictional relative's tuna-salad-and-cracker-eating bird (4,5)

'fictional relative's tuna-salad-and-cracker-eating bird' is the definition.
I can't judge whether this definition defines the answer.

'tuna-salad-and-cracker-eating bird' is the wordplay.
I cannot really see how this works, but
an anagram of 'tuna' is 'aunt' which is present in the answer.
'bird' could be 'poll' (poll is a kind of bird) and 'poll' is present in the answer.
A single letter 'y' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?