Some representations of ETs involved in abductions

The Grays 

Seem to range across a diverse spectrum of species, 

from relatively simple biological robots to highly spiritual beings.

Mantis (or Mantid) ETS 

Often in authority positions during abduction, tend to have more positive 

effect on people, more intelligent, doctors or guides.

Reptilian or Reptoid ETS

Appear in very negative forms but occasionally positive as well.