Dave is an orange fish. Frank has made many cameo appearances. His first appearance was in the episode, "Karate Choppers."
He is a relatively tall red-orange fish with light yellow/tan fins and light green lips, and wears a light blue top. He looks like Frank, except, unlike Frank, his eyes are on the top of his head. It is possible that he is a relative of Frank or that he is the same person because they look alike.
He comes up to SpongeBob and thanks him for the flowers, much to the annoyance of Patrick. In "Patty Hype," he crawls into the Krusty Krab, claiming that he has had no food or drinks in 3 days. SpongeBob immediately gives him a meal, but he leaves, saying that there is no theme in the Krusty Krab.