"Lizard-like creatures that have, over the years, adapted to life surrounded by lava. They are reasonably handy in combat situations (particularly in earlier levels), but their main asset is definitely their immunity to lava. Unfortunately, they are unsuited to work involving research or manufacturing."
— Dungeon Keeper 2 Manual
The Salamander has an immunity to fire, lava, and hot things in general. This allows them to wade through streams of lava that would prove a painful obstacle to your other minions, making them moderately good scouts (particularly in possession). This, coupled with their moderate combat abilities, fiery spells, and their love of training, makes them a fair addition to a Keeper's dungeon.
The Mentor's Thoughts[]
"Behold a Salamander; graceful ancient lizard who cannot be harmed by fire. He'll even wade through lava streams with no impediment." — The Mentor, Campaign Mode
"A Salamander has joined you. These reptiles are extremely hot-blooded, and will happily wade through lava." — The Mentor, Pet Dungeon Mode