Guppy is a plump and large killer whale who appears in Super Mario Galaxy. Despite his name, he is very cunning and cheats his way to the sea. The Toad Brigade greatly fears Guppy. Penguins, however, are deeply annoyed by him. He gives Mario tips on swimming.
Guppy is seen in the Sea Slide Galaxy, where Mario has to race him by going through eight loops in the sea. He also appears in other levels in Sea Slide Galaxy. Guppy also appears in the Deep Dark Galaxy, where Mario must go through eight loops again, but it is even harder than the first time, as he will summon the last ring in the middle of the three whirlpools. Also, the ring will disappear after a while if not traveled, which causes a loss. Mario will die if he misses even one ring.
- If Mario or Luigi touches Guppy's tail fin, or Guppy at all, he is hit as if he had touched an enemy, but he does not lose health. If you're on land with Guppy, you'll be thrown backwards if you touch him.
- According to the Prima guide for Super Mario Galaxy, Guppy was originally going to be a dolphin (Killer Whales are still a kind of dolphin, though) and a friendly character.
- The Prima guide also incorrectly referred Guppy to as a shark.