This is a SpongeKid SlightPants: Lunch Hour episode.
Spongebob, Patrick, Sandy and Squidward are having a consplay competition.
(Spongebob and co. are having a consplay contest)
Spongebob: (dressed as Mermaidman) I'm Mermaid!
Lunch lady: Mermaidman sucks! NEXT!
Sandy: (dressed as a cowgirl) YEEHAW! I'm a cowgirl
Lunch lady: I've seen worse. NEXT!
Squidward: (dressed as a clarinet) I'm an aritistic clari...
Lunch lady: This is a lunch room, not the art room (kicks Squidward to the art room)
Squidward: (from a distance) AHHHHH! (hits ground) Ouch.
Lunch lady: Bring in the pink, chubby one.
Patrick: (dressed as a pickle) I'm a Seahorse.
Spongebob: Patrick, thats a pickle.
Patrick: I didn't question your costume. AHH! (beats up Spongebob)
Lunch lady: Bravo! (claps) (curtains close)