While not exactly pigs, snails flying are still rather interesting:

Somehow, the animal kingdom's least-likely island-hopping creatures — land snails — have managed to jump from Europe to the Azores, then leap 6,000 miles of snail-dissolving ocean to the isolated Tristan da Cunha island group, deep in the South Atlantic.
...
There have been wind tunnel studies of how far juvenile snails from Greek Islands can blow in the wind. It has been calculated that small snails can be blown more than 10 miles.

"In the Pacific we have even tinier snails," said [University of Hawaii snail researcher Robert Cowie]. "What's more, most of them live in trees, where they could conceivably be caught on a freed leaf during a hurricane and carried for thousands of miles.

Whodathunkit?