Octoballoon

Octoballoons are inhabitants of the wetlands of Hyrule in A Link to the Past. Link only sees one of these mysterious creatures in his journeys. This octopus uses some method to hover above the ground, standing in wait of prey or danger. When it senses danger, it will bloat and explode, ripping its egg sac apart and releasing tiny larvae that roam around the land, which die or burrow into the ground a few moments after birth. Quite notably, only one Octoballoon is found in A Link to the Past, although it respawns as every other enemy in the area.

However, in the GBA version of the game, another Octoballoon appears in the Palace of the Four Sword during the way to the chamber where Link has to defeat Mothula for the second time.

Trivia

 * The Octoballon may have provided the physical inspiration for the Blowhog enemy from the Pikmin series.