Natarl

Among the aliens stuck on Denossus was a being with a distinctive helmet and webbed hands and feet. (COMIC: Land of the Blind)

Four of these beings were once at a beach in a valley. (GRAPHIC: The Dr Who Annual 1966 Contents)

Several of these beings were also seen on the Moon. (GRAPHIC: The Dr Who Annual 1969 frontispiece)

Behind the scenes
These aliens are Natarls from the film (1959).