Shark! Shark! is an Intellivision game originally designed by Don Daglow, and with additional design and programming by Ji-Wen Tsao, one of the first female game programmers in the history of video games. The player is a fish who must eat smaller fishes in order to gain points and extra lives while avoiding enemies such as larger fishes, sharks, jellyfish, lobsters and crabs. After eating a certain number of fish, the player's fish grows in size and is thus able to eat a larger selection of fish. However, while the larger fish becomes a bit faster, he is less agile than the small fish and has a harder time avoiding enemies.

Shark! Shark! was originally considered by Mattel to be a cute game for kids and unlikely to make strong inroads into the gaming community. The game was unexpectedly popular, forcing Mattel to quickly manufacture another batch of cartridges. The original cartridge run was only 5,600 units.