noun. I believe the technical term is "cuckooburger with a side of batshit."
Related term: nutsopath.
Real citation: “I would venture a guess your friends view you are a dangerous whackopath.”
(March 31, 2007, thisisby.us, http://thisisby.us/index.php/content/for_guys_mostly)
Made-up citation: "My friend has a very Seinfeldian dating story about a guy who ate everything--even steak--with a spoon. Quirky doofus or ex-con whackopath? Only his case manager knows for sure."