Mason was originally a rescue, found abandoned on one of the JC&D sites. He lost his leg after getting it stuck in wet concrete. It's unsure if he was dumped on the construction site, or if he was simply a stray that accidentally got stuck.

Currently he lives a happy life with Gouache, getting spoiled to bits by her. He is training to be a guard dog for her construction sites, but isn't very good at guarding yet (and Gouache isn't very good at training a guard dog from puppyhood). His real name is Mason, but Gouache's nieces have so lovingly called him Buppy instead.