Pig Connoisseur

I once knew a man from York,
he'd a strange obsession with pork.
Some wearing wigs,
strange were the pigs,
collected by the man from York.

One fine summer night,
with the sun shining bright,
a pig sprouted wings.
What terrible things!
And flapped off into the sky.

'Oh dearie me!'
my weird friend said,
'I had my collection completed,
and now I've lost Fred!'

Fred may be flying,
to this very day.
A bird? Or a pig?
None but Fred can say.