The little boy is a fish kid who appears in the episode "Lost and Found."
He is a light green fish who wears a red propeller hat with a yellow spinner and red overall pants with two white buttons.
Role in episode
The kid comes into the Krusty Krab, crying for his lost teddy fish. His crying annoys the customers and makes them gradually leave the restaurant. Due to this, Mr. Krabs starts to cry too.
Once SpongeBob finds the teddy fish in the Lost and Found and hands it to him, he says that he does not want it anymore and decides to have the Tylosaurus instead. As a result, the teddy fish is then given to Ginger.