Torch Slug
The Torch slug is a flame-based mollusk that haunts the catacombs of the Fire Temple in Ocarina of Time and several dungeons in Twilight Princess. Invulnerable while its flames are lit (although this does not apply when using the Biggoron Sword), the slug will dash towards prey or foe, slamming into them with great force, usually knocking medium or small sized creatures backwards onto the floor. It is known that weapons like a sword can be used to destroy their protective flame, uncovering a Grey, weak flesh that is the real body of the slug. Striking again will result in the death of the slug. Their signature sound comes from them crawling along the floor, resulting in a high-pitched rubber-like tone.
Trivia
The Pokémon Slugma and its evolution Magcargo are based on a similar concept.