Bud is the owner of Bud's Pets, the pet store in which the fish tanks that make up the world of Fish Hooks are contained. Bud is seen at the beginning of each episode, usually doing or interacting with something that relates to the episode's plot (the listing of what his store sells besides pets also changes accordingly with each episode's plot). Bud usually appears to be unaware of what is actually going on inside the fish tanks. The fish know him as "Big Blue". He appears to be very obese and has the appearance of a handy-man, so he may be the pet shop's janitor, too.
Bud never speaks, but occasionally makes sounds, which are provided by Dana Snyder. Bud is portrayed in photo-realistic "live action" by storyboard artist Sherm Cohen.