Hydroweasel

Hydro-weasels are so despised that their name has become a synonym for treachery. Beyond this, little is known, although it seems reasonable to think they inhabit or are otherwise involved with water. This may or may not imply an origin on a planet other than Cybertron. Atlantis, Arise!

Fiction

Beast Wars: Uprising

Bisk was known to fight hydro-weasels and other creatures lurkng in Cybertron's lower levels. Not All Megatrons