Fireboy and Watergirl is a browser puzzle-platform series built around two-player cooperation, where Fireboy moves through fire and Watergirl moves through water, and each must avoid the other's element. It became a staple of Flash-game culture and classroom computers, then lived on through playthroughs, speedruns, and nostalgic edits long after the Flash era ended. The pairing itself became shorthand for opposites working together, which is why short clips from the games still appear in memes, edits, and reaction videos today.