There are a lot of Petz codes, so much, I can't list them all. Mostly because I don't know all of them. You can search on google. I remember some though: havfun, petcat, thirst, and iloveu. Like I said, you can search on google. I'm sure you'll find lots of codes. Some codes unlock the same thing so don'y be surprised if you typed in a new code and a message appears saying you already used this code. By the way, if you want to type in a code, just tap the suitcase, and then tap the key. The screen will change, and you just need to type in the code and tap okay/enter.