>>114619145The character in the picture was a prominent background figure used a fair amount to fill space when they needed characters in a shot. He then started appearing more and more as if he would become part of the secondary cast. Come this episode, he got his first speaking role.
The context of this scene is he and everyone present ate some magical icecream that gave them temporary superpowers. Out of the blue he announces he thinks he has the ability to breathe underwater and rushes out of the scene. Later on in the same episode, they're all in the same building and the kid is nowhere in sight (but everyone else from earlier is). What makes it even more stranger is the kid got removed entirely from the show after episode 20 (some speculating the episodes aren't in chronological order). Hence the whole joke about the kid drowning in the lake he was testing his supposed superpower in.