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.
Ned's Newt
The series begins with Ned finally scraping up enough money to buy a pet. However, upon reaching the pet store, the only thing he can actually afford is a newt. Dubbing his new pet "Newton", Ned quickly tires of it, since Newton just lies on the rock in his bowl. Complaining to the pet store owner that his new pet is not very active, the owner gives Ned a can of "Zippo for Newt" pet food but warns Ned not to give his pet too much. Ned feeds Newton a little, but Newton does nothing. Ned leaves the can beside Newton's bowl and goes to bed.