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.
Rough-skinned newt
The newt produces a neurotoxin called tetrodotoxin (TTX), which in this species was formerly called "tarichatoxin". It is the same toxin found in pufferfish and a number of other marine animals. This toxin targets voltage gated sodium channels via binding to distinct but allosterically coupled sites. Because TTX is much larger than a sodium ion, it acts like a cork in a bottle and prevents the flow of sodium. The reverse binding to sodium channels in nerve cells blocks electrical signals necessary for conducting nerve impulses. This inhibition of firing action potentials has the effect of inducing paralysis and death by asphyxiation.