waterdog

or wa·ter dog

[ waw-ter-dawg, -dog, wot-er- ]
/ ˈwɔ tərˌdɔg, -ˌdɒg, ˈwɒt ər- /

noun

any of several large salamanders, as a mudpuppy or hellbender.

Origin of waterdog

First recorded in 1855–60; water + dog