Riding lizard
From Forgotten Realms Wiki
Riding lizards are large reptiles used as mounts by drow in the Underdark. These horse-sized lizards have wide-splayed legs and are built low to the ground. Their keen sense of balance and ability to walk on walls and ceilings make them the ideal mounts for dark elves on patrol. Most noble houses have at least a handful of the valuable lizards, and the larger houses have entire squadrons of lizard cavalry.
