The Little Green Men (voiced by Jeff Pidgeon, Debi Derryberry, John Lasseter and other cast members on helium) are toy aliens with three eyes in the Toy Story franchise.
In Toy Story 2, Mr. Potato Head saved three Little Green Men from falling out a Pizza Planet Truck window, and the little guys became attached to him. Mrs. Potato Head chose to adopt the three aliens as her children, much to her husband's dismay.