PetVille wants you to free the mysterious creature within

What could this be? in PetVille
What could this be? in PetVille

PetVille is the second Zynga game to launch a quiet and unannounced new feature this week. When you log into your pet's room, you'll find that PetEx (a spoof on FedEx) has transported a creature caged inside a pet carrier. It looks scared and cries a lot, and your pet is obviously worried.

Locked pet carrier in PetVille
Locked pet carrier in PetVille

Your first instinct is to let the poor thing out, but you'll need to get the secret combination for the lock through e-mail!