Yt-MejKot

The Yt-MejKot (pronounced yit-mej-kot) is a monster found only in the TzHaar Fight Cave. It appears first in Wave 15. It resembles a very tall, lizard-like humanoid. Its melee attack is a powerful slash from its claws that hits up to 28 hitpoints. The Yt-MejKot also has the ability to heal up to 10 of both its own hitpoints and those of any other monsters around it once the targets drops below half health.

These are large monsters and are easily blocked by other monsters or the rocks in the cave. Yt-MejKots appear to only heal themselves whilst below half health, so it is very likely they will not heal at all if you are ranging them from a safespot. Yt-MejKots are a good source for healing hitpoints if the player has Guthan's equipment, due to the fact they recover their life points using their ability.

Trivia

 * Yt-MejKot, in the Tzhaar language, could be translated as "Cold-Mage-Protect" or "Dead-Priest-Save". "Yt" in TzHaar is cold, freeze, or dead. Yt-MejKot looks like a lizard, and lizards are cold blooded. "Mej" means priest or mage. In this case, it's probably a priest as the old examine text is "Holy Reptile...". "Kot" means save or protect. Yt-MejKot heal themselves and other nearby Fight Caves creatures, so they are protecting and saving them.
 * They seem to heal themselves every 2 attacks they use, but this tends to occur only when meleeing them or standing very close to them.