Are there any case of commonly practiced pedophilia among the animal kingdom?

Apes. Specifically chimpanzees.

As Ethan pointed out, one of our closest relatives.

Are you asking because of the claim of other animals being gay? That's a response to people claiming its unnatural. But being unnatural or natural doesn't make something good or bad. Nor does having urges justify actions if such actions are likely to harm others. Homosexuals having sex with other guys is not a problem. There is no reason to expect them to not have sex with their desired class of partners. Being a pedophile does not mean you do anything to harm others.

Bonobos, one of the two types of chimpanzees: "Sex functions in conflict appeasement, affection, social status, excitement, and stress reduction. It occurs in virtually all partner combinations and in a variety of positions." I agree that if you're trying to find anything relevant to humans at all, the insect world is not the place to look. And if the practice is part of the reproductive cycle of an organism, in an important sense they are not sexually immature.

There's a variety of fig wasp that has males mate with freshly hatched females. That sort of thing may or may not be more common than known, but I think it's a mistake to call it 'pedophilia' when it's not a human, or at least hominin, behavior.