A cog hypnotist is one that can induce a state of unconscious, obedient tranquility upon willing participants through eye contact. Cogs with strong hypnotic abilities can briefly control properties like the victim's self esteem, moral and state of arousal and can also induce hypnosis upon an unwilling participant.
Several incidents can induce the ability of hypnotism through cogs. Research has been done on a cogs' ability to be hypnotized and to see if one can be deliberately programmed to be "hypnotized" (basically trying to create this power in cogs straight from the factory) but the full magic properties cannot be implemented into one that way. A true hypnotist cog forms when they receive major trauma, particularily to the head. Their eyes will become deformed in some way, usually involving psychedelic colors.