The Chum Coliseum is a replacement for the Chum Bucket built after demolishing it. Of course, the idea to build the coliseum was a scam to get Plankton all of the Krusty Krab's customers. This stadium was the location where the gladiator show was held. Patrick is against a sea lion in the gladiator show with blood sausages around his throught. The coliseum is only seen in the episode Spongicus.
 Plankton's Opening Speech
After the stadium opened, minutes before the stadium's opening fight, Plankton gave the following speech: "Greetings, citizens (soon being slaves) of Bikini Bottom. Behold my imperial Chum Coliseum! I vow to introduce to this fair city, culture, in the form of hand to hand grappling! I intend to enrich your lives culturally, by exhibiting the moist spectacle of gladiators in mortal conflict! My corporate under writers told me to mention that it's free! Come on! Come on! Remember, kids love gladiators."
- The outside of the coliseum looks like the old Roman coliseum seen long ago.
- The coliseum has a giant monitor that says "GLADIATOR SHOW 2-DAY!" The screen is also Plankton's announcement system.
- The top of the coliseum has a circle of red flags.
- The inside is lined with seats made of sandstone slabs. There are stairs leading into the seats, and there is also a special seat that Plankton and Karen sit in (with a red upholstered seat of brown wood that's surrounded by a "fence" made of seaweed reed and bamboo). The heart of the arena is where the gladiator fighting takes place.
- The seating capacity is 1,700
- Surprisingly, the exits are in the heart of the arena.
Since the stadium is not seen in later episodes, nobody knows what happened to the coliseum after the episode. It is likely that Plankton tore it down afterwards because the "boring" fights and the inedible food made the arena unpopular and nobody would visit it.