Gyorm

Gyorm are strange fish-like enemies that appear in and. They hover around the Swamp Palace and the Cove of Transition  in unusual spiked shells. These shells are both a form of locomotion and defense, as a Gyorm cannot be harmed while hiding within it. They are not particularly aggressive, but they will cause harm to Link if they come into contact with him. To defeat a Gyorm, they must be pulled from their shells using the Hookshot or Gripshot. Once dragged from the safety of their shell, they are far less mobile, and vulnerable to the Master Sword or the Hero's Sword. They will attempt to return to their shell, and must be defeated before they can.

Gyorm hover over water rather than swim in it, and may not actually be aquatic at all, as dragging them out into deep water will cause them to drop in and be defeated.

A Gyorm's empty shell can be picked up and thrown by Link, and can be used to damage enemies or activate switches.