X Minus One - The Last Martian (#63) 

08/07/56, episode 63
This episode provided by the Old Time Radio Researchers Group
www.otrr.org
A man tells a newspaper reporter that he's the last living Martian, Yang-AnDow. So the two sit down, and have a beer, and the Martian tells how he saw everyone on his planet die, including everyone in the planet's largest city of Xandar (I love those Martian names). He has taken over the human form Howard Wilcox to disguise his 3-foot high, tentacled Martian form. How he got the form and how he got to Earth from Mars and are there any other Martians in New York City, well you just have to listen to believe. (from "The Critical X Minus One" by Jim Fanisher)
Credits (Goldin): Fred Collins (announcer), Santos Ortega, Ernest Kinoy (adaptor), William Welch (producer), Daniel Sutter (director), Elliott Reid, Frederic Brown (author), John McGovern, Mandel Kramer, Patricia Weil, Ralph Bell