The Tiger Salamander is a member of the family Ambystomatidae, the mole salamanders, a North American group of heavy-bodied salamanders with distinct costal grooves, and laterally compressed (side to side flattened) tails. Matsuda et al. (2006) described them as having 'large blotches of yellow, cream or dirty white on a black, grey or dark brown background. Juveniles can be irregularly mottled and spotted without discernable blotches.' The Tiger Salamander is the largest terrestrial salamander in North America after the Giant Salamanders, and is active only at night. Neoteny is known from both western subspecies (Lannoo 2009).
According to Lannoo (2009), adult tiger salamanders can be terrestrial or aquatic (neotenic). Neotenic adults persist only in fishless, permanent water bodies. Lannoo states that: 'Terrestrial adults burrow and require deep friable soils. Tiger salamanders actively burrow by using their forelimbs (Gruberg and Stirling, 1972; Semlitsch, 1983c). Animals tend to live near the surface (12 cm deep; Semlitsch, 1983b) but can be found deeper'.