The large larvae of Tiger Salamanders are usually known as waterdogs, and are used extensively in the fishing bait and pet trade.
These larva are entirely aquatic, and characterized by large external gills and a prominent caudal fin that originates just behind the head. Limbs are fully developed within a short time of hatching. Some larvae, especially in seasonal pools and in the north, may metamorphose as soon as feasible. These are known as small morph adults. Other larvae, especially in ancestral pools and warmer climates, may not metamorphose until fully adult size.