Nejiron

A rock-like creature found on the path to Ikana Canyon on Majora's Mask. It's composed of gun powder, thus making it explosive. It hides underground and uses the element of surprise. It attacks by rolling, crushing Link doing relatively minor damage (In fact, after getting the heart upgrade, none). It must be destroyed using the hookshot or bomb, arrows and fire arrows don't seem to have any effect. These lumbering, rolling creatures are easily avoided.

"That's a Nejiron. Don't get too close to it. Sniff...Sniff... It smells like gun powder!"