I have to say, I knew that Penpy was adorable, but I honestly didn't expect it to be this adorable. If you are on the lookout for vintage alternatives to the Tamagotchi, then you will love this Penguin pet. I'm not sure if growth is based on how you care for it, but mine eventually turned into an Erect-crested Penguin. I loved the animations. From what I remember, this pet has two games and two separate meters. One meter tells you all the basic information about the pet, such as age and weight, and the other meter tells you happiness. The penguin starts out as a cute little blob and eventually gets legs and a more prominent beak. The transformations were adorable because it turned into a completely different penguin every time. These seem sort of rare to me since I only see one or two on ebay at a time. The shells seem to come in all different pastel colors. I've seen it in blue, purple and orange (the one I have). Pretty sure it comes in other colors as well. I really like the shell because the screen is flush with the shell, and it is completely round, which is something you don't see often. He is based on Gyaoppi programming, but he is different enough to be worth buying in my opinion. The only thing I didn't like was that it lacks a background for the screen. Virtual pets with plain grey backgrounds make me kinda sad :/ The buttons were also plastic instead of rubber, which gave it a sort of cheap feel. On the other hand, plastic buttons probably don't suffer from chipping away the way the rubber ones do, so maybe some people might prefer this.

Here are some pictures of the one I have:

Price

I think I bought mine for about $15 from Jennifer Eden of youtube in the facebook groups, so mine was used, but in package. I see a couple of others on eBay for the same price, so I would say they are worth $15-20 depending on condition and packaging.

Growth Chart:

I do not believe there is a growth chart out there :(