Joozians
The Joozians are an alien race who control all media in the universe. They are also responsible for the reality TV show that is earth.
Their first appearance in South Park also gave some insights into their reproductive methods. Male Joozians have an appendage on each shoulder with a sort of spiky head at the end called a jaggon, which becomes hard when aroused. Male Joozians also receive some stimulation from their thrusher, an orifice on their back. Female Joozians have additional organs called heckmars, which resemble human breasts, though there are four of them.