Incidental K4[1] is one of Billy's friends who also attended Poseidon Elementary School with Mr. Krabs and Plankton. He appears in the episodes "Friend or Foe" and "A Life in a Day."



In "Friend or Foe," specifically after the scene at Stinky Burgers, he is shown with olive, brown skin, dark green eyes, dark blue shorts, and light yellowfins.

In "A Life in a Day," he wears a white T-shirt and light blue shorts, and he has tannish-green skin and dark green fins.

Role in series

"Friend or Foe"

When first introduced, he is a schoolmate of Mr. Krabs and Plankton at Poseidon Elementary. He is also one of the various friends of the school bully, Billy, who teased and tormented Eugene and Plankton as children. According to his friends, he will eat anything. He was the first to try Plankton's chumburger, but when he eats it, he spits it out due to its toxic flavor.

"A Life in a Day"

He makes a cameo at Goo Lagoon, where he is making a sandcastle alongside another fish.


  • Big Johnny resembles a younger version of Incidental 6 and features many characteristics from him, such as his olive-green color skin and the purple T-shirt and blue shorts he wears.


  1. ^ Friend or Foe storyboard
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