Y'tossi

Y'tossi is a marilith that appears on the 5th level of Watcher's Keep. She appears along with Nalmissra, Y'tossi, Ameralis Zauviir, a Hive Mother and Xei Win Toh  when the last key of the Final Seal is turned.

In addition to common demon immunities, Y'tossi is immune to backstab and +1 magical weapons. She is hasted, has a natural ability to detect invisibility and regenerates 2 hit points per second. She is equipped with Gauntlets of Extraordinary Specialization and a Sword of Flame +1.