What is planet pet?

As an AI language model, I'm not aware of a specific planet named "Planet Pet" in our solar system or anywhere in the known universe. However, as the term "pet" refers to a domesticated animal kept for companionship, it is possible that someone could create an imaginary planet named "Planet Pet" where all kinds of pets from different galaxies gather and live together. But without any more context or information, it's challenging to provide further details about such a hypothetical planet.