The Chumstick, also referred to as Chum on a Stick, is one of the main chum food items made by Plankton and one of the many chum products provided at the Chum Bucket. It has two forms: as a hot dog shape or a square. They are known for their disgusting taste and making people vomit. The ingredients to the Chumstick are revealed in the episode "Spongicus."
Patrick Star is the only person in Bikini Bottom who can actually eat raw chum without throwing up, getting sick, or even dying. Sandy Cheeks also had to eat as much raw chum as she could, but was horribly mutated by it.
In the episode "Chum Bucket Supreme," Plankton feeds one to SpongeBob, which causes the disguise SpongeBob and Mr. Krabs were hiding in to explode. SpongeBob was then seen wiping his tongue with a sponge obviously disliking the taste.
In normal episodes, they are sort of in a shape of a corn dog, but in "Spongicus" they are a rectangle shape on a stick. Both times they are a dark red color but with a different kind of stick on them.