From Roswell to Buff Ledge, we have been obsessed with alien abductions and UFO sightnings since the 1950s. Most alien sightings fit three basic types: Grey, Reptilian, and Nordic.
This is the most commonly sighted extraterrestrial being. The general description is shorter than the average person with smooth gray skin, and large black eyes. Greys seem to be able to only communicate telepathically. Their abductions are mainly for scientific research.
Reptilians don't seem to favor Earth creatures very much seeing as though they are responsible for only 20% of reported abductions. Their appearance is taller than the average human, muscular, have tails, and if it wasn't obvious- reptilian. Abductees claim that they are a rough bunch that use fear and intimidation on their captives.
As if humans weren't narcissistic enough, we have to insist there are aliens that resemble us. They are said to be in good shape with blonde hair and blue eyes. Like the Greys, they have the ability to communicate telepathically. This species has inspired the ideas that we descended from aliens and certain religious groups such as Raelism.