Unlike some of their under-bridge-dwelling cousins, these Trolls like things heated-up a little.
They often dwell on the fringes of populated areas, where they are known to pop out, cause trouble, and retreat back into the shadows.
Occasionally a group of them, known as a “stench”, will invade a human settlement, where (with perfect mimicry) they will set the inhabitants to arguing amongst themselves. Only after any ensuing carnage is over, will the the stench of trolls re-emerge to pick through the festering and burning remains of their victims.

These minor elementals are born from molten rock. Too weak to form an actual Lava Elemental, they simply float our of the lava and explode shortly afterwards.