Dirty Dan is a mentioned character in the episode "Survival of the Idiots."
029a - Survival of the Idiots 348

SpongeBob as Dirty Dan.

He is the leader to Pinhead Larry, which together they make a crime duo / gang and apperantly do it in Texas. Him and Pinhead Larry are said to be enemies of Sandy Cheeks, as she had dreams of her catching Larry and Dan, as its most likely that she never got to catch him and Pinhead Larry when she was still in Texas.