Cumulus

From Artemis Fowl

Professor Cumulus was a behavioral specialist who reviewed Julius Root's iris-cam video of the meeting with Artemis Fowl II during the Siege Of Fowl Manor.

He debated with Dr. Jerbal Argon during Book 1, as to whether Artemis was lying or not. He and Argon found out (in the first book),Artemis Fowl's "mistake", which allowes the faries to enter and collect their gold after Fowl was dead. Interestingly, in The Arctic Incident, Opal Koboi states that her parents are in an asylum, named Cumulus House.