Billy is a kid fish who first appears as the secondary antagonist of the episode "  Friend or Foe."
He is a light purple fish with purple fins, faded-blue lips and wears a red shirt and a white and blue cap.
Role in series
Billy is shown as the leader of a group of class bullies at
Poseidon Elementary School who constantly makes fun of Mr. Krabs about his clothes and calls him "Rag Boy" and also bullies Plankton for his small size and brilliant intelligence.
He is among a small mob of troublemaking teenagers who run rampant through
Bikini Bottom, attacking people with ketchup.
He is seen in his
mom's car, commenting over Mr. Krabs blabbering in his car. Additionally, his name is revealed in this episode when his mother says, " Billy, mommy's watching the road right now."
He appears on the title screen.
He appears as a baseball player at the baseball field.
He appears in the Bikini Bottom field.
He is one of the kids who star in the horror film
Fisherman 4: Attack of the Hook
He is seen running away from school after hearing Squidward's horrible kazoo sounds in a flashback.
He appears in
Dylan's surface party.
SpongeBob gives him his leaf blower.
He is the first child bully to be shown in the series.
Despite being a teenager in "Picture Day," he does not look nor sound any different than he does as a first grader in "Friend or Foe."