Yeti

The Yetis, also called Abominable Snowmen are a race of elusive humanoid hairy giants often spotted in the Himalaya Mountains on Earth. Although principally a cryptozoological phenomenon, they have been represented as aliens, or with alien connections in quite a few instances in science fiction:
 * In Isaac Asimov's 1953 short story "Everest", Jim Robbons is the first man to reach the top of Mount Everest, and discovers that the Yeti are actually benevolent aliens from the planet Mars, who are carefully observing mankind. They give Robbons food and technology to help him survive the snowstorm that was delaying the arrival of the rescue team. Having evolved in the thin, frigid Martian atmosphere, the Yetis are perfectly well suited to survive in the Himalayas and move at considerably fast speed, given the small quantity of oxygen available. So adapted are they in fact that their species is unsuited, perhaps even unable, to live on any other area on planet Earth. They can communicate with Humans telepathically.
 * Robot Yetis of extraterrestrial origins have also appeared in two story arcs of the sci-fi series Doctor Who, namely "The Abominable Snowmen" and "The Web of Fear", both featuring the Second Doctor; and in the spin-off movie Downtime, which does not feature the Doctor at all. The robots' controlling units consist of crystal-like spheres and are ultimately controlled by a vast, evil non-corporeal intelligence which is seeking ways to invade our material plane (in some novels, the Great Intelligence is identified as being none less than Yog-Sothoth). It is implied that the Robot Yeti were based on a real species of rather timid and peaceful creatures inhabiting the Tibetan mountains; one of which does make an appearance in the end of "The Abominable Snowmen" arc.
 * In H. P. Lovecraft's mythos, the Mi-Go were known as the inspiration for the Yeti. Despite their non-humanoid nature, they were specifically referenced as the source of the Yeti myth in both The Whisperer in Darkness and At the Mountains of Madness. Furthermore, the name Mi-Go is similar to the native Tibetan name of the creature, Migou.