There are various alien speces out there, that use powers natural to their species. All member of such a species have access to the powers, though few developt them fully.
Aliens need not come from outer space. The Rockwalkers of the Inner Earth, fish-men of Atlantis and bird-men of the Himalayas are all famous.
Aliens have a set of innate powers specified when the race is created. They should make some kind of sense in that a people all displaying these powers and weaknesses could reasonably survive. Be warned that any race a player designs is likely to crop up as villains as well.