Salamander (Franchise)

Salamanders are mentioned in the game, School of Dragons during the expansion "Rise of Stormheart".

Description
Salamanders are generally lizard-like in appearance and body shape, but are amphibians rather than reptiles as lizards are. Salamanders (Order Urodela) are most closely related to frogs and toads. Salamanders can come in a variety of sizes and colors, depending on the species. They have porous skin like frogs and need to stay in some sort of moist environment; some species are nearly completely aquatic. Most typically have a slimy coating on their skins, and some are poisonous. Salamanders have a unique ability to regenerate limbs, not just tails as lizards can.

Function
Salamanders have little to no use in the How to Train Your Dragon Franchise, nor in real life. Their ability for regeneration is being studies scientifically, however.

School of Dragons
Salamanders are mentioned as creatures that may occupy vernal pools. Some vernal pools - temporary pools of water - appear on Hobblegrunt Island during the events of the game expansion, "Rise of Stormheart".