Señor Taco is the owner of the restaurant Taco Sombrero, in the episode "SpongeBob You're Fired." He has a Spanish accent.
He hires SpongeBob to make tacos for him. After SpongeBob fails to do this, he fires him. When the taco patties are successful, he kidnaps (or tries to kidnap) SpongeBob, and is stopped.
He is a purple fish dressed in a zip-up taco costume. He wears black boots. He also has a grey mustache.