The Chum Bucket is a restaurant that was started by Plankton in the 16th century. The idea was that fish eat other fish, and therefore the best way to sell food is to promote cannibalism. The Chum Bucket was born. It's greatest rival is the Krusty Krab. The Chum Bucket is currently rated #48176593820 on the list of most popular restaurants with a grand total of twelve customers in the six hundred years it has been running.
It is the most evil restaurant that ever existed.
The Chum Bucket was first created somewhere in Hell because Dora the Explorer decided they need a way to feed all of the dead fish while still satisfying The Devil's sadistic desires. Plankton approached Dora with his idea, pointing out it would satisfy both of their problems. Dora signed the 5 year contract, and the Chum Bucket was built.
Three days into business, Dora noticed that all of the fish from Hell were going to the Krusty Krab. They were literally walking right out of Hell just so they could go to a fast food restaurant. She terminated the contract (demons can do that), and teleported the Chum Bucket to the open lot across the street from the Krusty Krab. It still operates there to this day.