Dinkie Dino (or RakuRaku DinoKun) comes to mind. I've played with mine a couple of times; it's cute, fun, and pretty simple. As for purchasing, your best bet would probably be to search "Dinkie Dino" on Ebay. There are a few on Ebay now if you're interested! Unless you don't mind getting a knock-off version of the Dinkie Dino, try and take a close look at the packaging (if available) and make sure it's not one of those "32-in-1" pets.