A Blogg is a species found in the GameCube game Metroid Prime 2: Echoes. They are large, violent sea creatures who'll ram into anything that attacks them - or anything that they spot. They only have one weak spot - which is in their mouths. They'll only reveal their mouths right before they charge you, suggesting that they more than a likely plan to eat anyone they attack.
Their young, Blogglings, are not nearly as powerful, and oftentimes must rely on their parents for protection, while otherwise they're nearly defenseless.