This word is a coalition of words, the first one being the 'tard' from the end of retard. The 'helm' comes from the word helmet which can mean a man or hermaphrodites bellend. Therefore by calling someone a helmtard you are calling them a retarded bellend.
Ruler of Lake Titicaca. Rumored to have a bunghole that gets very angry if it does not receive toilet paper. Cornholio the Great is often seen walking around with his shirt over his head and his hands in the air, chanting songs about his power, and his bunghole.
"I am Cornholio! You do not want to face the wrath of my bunghole, for I need TP!"
Butthead: Shut up, Beavis! (uh huh huh huh)
Beavis: Um, okay. (heh heh heh heh).