The grey, aliens, there are many dimensional levels, not only in the third dimensional level, they are little people a little more than 1.20 metres tall, with very large heads and large eyes, and gray skin
In ufology, grays, also called the extraterrestrials of Roswell and Los Zetas Reticulianos, are some of the alleged various forms of extraterrestrial life and most famous currently known that appear in the modern conspiracy theories of the concealment extraterrestrial and other phenomena associated with the paranormal and ufology.
In the US popular culture they have replaced the classic “Little green men”, known in English as “Little Men green”, as the typical form of extraterrestrial life.
When the Zerg arrived for the first time to the Koprulu sector, were united under the absolute obedience to the collective wisdom known as the supreme mind. This controlled the acts of each creature in the Swarm and worked through a hierarchy of sapiencias minors

you can modeling this alien in cinema 4d for free