Guinea pigs and bunnies can get along, but it can be dangerous for your pig, since a bunny could unintentionally hurt or even kill your guinea pig with his powerful legs.

I'd recommend getting another pig (a male) to keep him company. How old is your pig? Sometimes male pigs can be territorial, especailly if they're older, so be careful introducing another pig to him, to make sure there's no fights.

Good luck. I hope Squishy will like a friend. ^_^