Tweety, Protector of Birds

All other bird creatures you control have hexproof.
If a bird creature you control would die, Tweety gets +2/+2, flying, and trample until end of turn.
In an experiment gone wrong, Tweety was accidentally transformed into a giant mutant, who then killed his master and saved the other test subjects. He now wanders around Innistrad looking for homes and food to take care of his friends.