Spotted paddle-tail newt
"Pachytriton" species are stout-bodied, smooth-skinned aquatic newts. Their heads are large and flattened, and they have conspicuous labial folds and short, stubby legs and toes. They breathe through both lungs and skin. 
"P. brevipes" ranges from 5.5 to 7.5 in as an adult. It has prominent labial folds, long digits, and smooth skin, which differs from the tuberculate skin typical of newts.
Plane (Dungeons &amp; Dragons)
Air- and water-breathing visitors to Neth can breathe and speak in Neth's fluid normally. If they swim around unnoticed, they might see organ buds larger than city blocks, beings behind membranous capsules, and the humanoid antibodies of Neth mindlessly going about their business. Every part of the living demiplane has a soft, pink glow. Neth can also flush the fluid wherever it wants, carrying visitors along with it, usually to the Visage Wall to be questioned.