Pip

Pip is a small rough-haired black-and-white terrier who lives with Twolegs near the Horseplace that ocasionally barks at cats and sometimes chases them.

Dark River

 * He appears briefly, shown chasing a group of RiverClan cats. Hollypaw and Willowpaw are spotted by Pip on their way back from the RiverClan camp, and must run over the WindClan border to escape.

Trivia

 * There have also been mentions of a dog chasing cats in the other books, which most likely was him.