Harry Potter and the Chamber of Secrets
Fang is Hagrid's rather slobbery boarhound. When Hagrid gets taken away to Azkaban temporarily, Hagrid leaves Fang in the care of Ron and Harry. They bring him with them into the Forbidden Forest when they go looking for spiders. Sadly, Fang doesn't help do much against Aragog's kids; it's really Mr. Weasley's car gone wild in the forest that saves Harry, Ron, and Fang.