A Remster
A remie, a remtard, or a retard is someone who’s got a brain like a bag of moldy chips. They can’t think straight and usually make bad life choices.
My uncle is a remtard. He married a goat. It was the worst decision ever.
My teacher called me a remie because I drew a goat on the board instead of doing math.
My dog is a retard. He tried to eat my homework. It was a disaster.