A lava keeper

Level 55 · Fire Elemental · Warrior · Dragon Necropolis

Found at the southeasternmost tunnel, #12 on the map, in the pool of lava overlooked by a group of Chetari. Not connected to the Chetari faction and won't social with them, but do social with each other. Note that there is a dispel trap (4 slots) and a net trap, both of which will break your invisibility, on the way to these keepers. I don't believe the traps are marked on the map.