Incidental 21 is a quiet fish who makes various cameo appearances throughout the series, beginning with the episode "Ripped Pants."
He is a light orange fish with big orange eyes and has brown fins and lips. He also wears a cyan-colored shirt.
He is usually seen as a customer at the Krusty Krab.
Role in series
He is one of the many fish surrounding Incidental 155 while he is holding SpongeBob, who is believed to have drowned, and later appears cheering in the audience during SpongeBob's song.
He sings "The Very First Christmas" along with a bunch of citizens.
He appears several times as one of the many customers participating in the Krusty Krab bulletin board.
He can be seen at the beginning sipping a soda at the Krusty Krab.