Dale is a background fish who appears in several episodes as an extra in the Krusty Krab and various other locations. His ex-girlfriend is Abigail and they are seen together in numerous episodes such as "Krusty Dogs" and "Trident Trouble."
He is a faded brown fish with a light-brown mouth and black eyes. He wears a red tank-top.
Dale is shown to be a kindhearted person, although he has an antagonistic streak. Like most of the other Bottomite fish, he'll join the town in civil unrest in support of certain causes. He is shown to have a distaste for boating school and isn't afraid to exhibit his rebelliousness, as he cut class an inexcusable number of times.
Dale also seems to be a bit emotionally sensitive, as seen when he cries upon Squidward stealing his food and insulting him in "Le Big Switch."
He is a Krusty Krab regular and enjoys their Krabby Patties, and is shown to eat their food like a pig.
Dale seems to enjoy candy in the shape of fish, but apparently this kind of food is illegal in Bikini Bottom.
In "Ditchin'," he gets arrested for eating Quasi-Gummy Chewy Candy Fish because it is "of his own kind." It is then revealed that he used to be a good student in boating school until he started cutting class, which lead him into criminal notoriety. This scares SpongeBob since he is doing exactly the same thing.
In the episode "Porous Pockets," it is revealed he is allergic to dairy - although he may have been lying about this just so SpongeBob would give him money.