Clog

Clog is a strange hairy creature in the Mario Brothers Plumbing house. He acts as an enemy to the brothers. He clogs up pipes in the Mario Brothers Plumbing and appears in a few episodes; he also appears in The Super Mario Bros. Super Show!. He has limes for his eyes and is a mess of brown, shaggy hair. He is not to be confused with the Clog Monster, a similar monster to him that appears in another episode and does the exact same thing that Clog does.

A clog is also a common name for something that "clogs" a drain or pipe hence the name.