Octoballoon

The Octoballoon is a rare creature and an inhabitant of Lake Hylia in A Link to the Past. As a relative of the Octorok, it has a similar appearance, but appears massively bloated and floats a short distance above the ground. It will float towards Link before exploding, scattering small Octoroks into the air and across the ground that will hurt Link if he comes into contact with them. They will bounce around before disappearing after a few moments, although they can be destroyed before this happens. A floating Octoballoon will also explode if struck, so there is no way to destroy it safely. It is unclear if an Octoballoon's explosive behavior is simply a bizarre defensive technique of the species or if an Octoballoon is simply part of an unusual reproductive cycle of the Octorok species. Quite notably, Octoballoons can only be found in one single location in A Link to the Past, on the eastern shore of Lake Hylia.

In the GBA version of the game however, a single Orange Octoballoon appears in the Palace of the Four Sword alongside Orange Octoroks in an icey room on way to the chamber where Link has to defeat Mothula for the second time. It behaves the same as a normal one, but will usually leave behind a smaller number of mini Octoballoons after exploding.