Someone who is seriously mentally deficient i.e foaming from the mouth. Somebody who lacks even the most basic social skills and who finds it extremely difficult to communicate with other humans.
Ben is a horror show over enthusiastic trogoid
That trogoid had to be escorted out of McDonalds in a straight jacket because he had a grand mal seizure when he saw Ronald McDonald
That trogoid just drooled down my brand new t-shirt, im going to fucking make his life a living hell