William Krabs was the owner of the Krusty Kantina. Unlike Mr. Krabs, who has a lot of money, William Krabs was broke because Dead Eye Plankton took all the money he earned. William Krabs first appeared in the episode "Pest of the West" and so far, that was his only appearance. Although his first ancestor who had the Krabby Patty, King Krabs was before him, this ancestor didn't have the Krabby Patty formula, unless "Dunces and Dragons" does not take accurate place in the timeline of SpongeBob, he did not want to reveal the family recipe while Dead Eye was around, or the Krabby Patty was never known to him. It is possible that he might have a salty/cheap attitude like Mr. Krabs. He sells alcohol drinks, strangely having milk also.
He looks exactly like Mr. Krabs, but wears a western style overalls: a green tie and pants without a belt.
He appears to be a little less cheap and selfish than Mr. Krabs, possibly due to his fear/phobia of Dead Eye Plankton.