Kathool Atchoo made its first appearance MechQuest as a the guardian of the underwater ruins.
Kathool Atchoo's role is expanded in DragonFable where it acts as the main antagonist of the Water Orb Saga and is responsible for the sudden disappearance of the Water Elves. He calls the Water Orb the Dragonheart Shard for an unknown reason.
Kathool rested at the bottom of the sea areas of The Span, awakening upon the defeat of the three Proto-Chaos Beasts Carnax, Fluffy the Dracolich & the Dragonoid. The beast was later defeated by the players, exchanging some words to them remarking that they would later meet again. After Iadoa's defeat, a vision of Kathool appears to voice some final words.
- When he casts Mind Twist, he can regenerate some of his health until his shield is broken.
- So far, he is the only Chaos Beast capable of speech.
- He first appeared in MechQuest.
- His full name is Kathool'Atchoo.