Some pets have the words "PPS" on their picture. This stands for Peter Pan Syndrome. It means that your pet will be a baby forever!
A quote from the FAQ page on CS:
"What is this text PPS on my pet?
- This means that your pet has been born with a special syndrome called "Peter Pan Syndrome". Your pet will never grow up past the puppy stage, so you get to play with it as a puppy forever! Yay! :)"
PPS does not only appear on dogs, regardless that the quote only mentions puppies.
- Most PPS pets are worth more than a fully grown pet from that litter