Perseus Team

Perseus Team is a Special Sun badge on Khan Academy. According to its KA page over here, its requirement is: Trained by the legendary Perseus himself, you are a fearless creator and wielder of interactive tools. Ben Eater, a Khan Academy staff member most notably has this badge.

Ben Eater is the lead exercise developer on Khan Academy so its description matches what he does.

Only content creators can achieve the badge, and it is impossible to get by normal users.