In the original film, Invasion of the Saucer-Men, that this comic parody is based upon, veteran character actor Raymond Hatton played the part of shotgun wielding Old Man Larkin.
According to the Internet Movie Database, Hatton acted in over 500 movies, going back as far as the earliest silent films. His first known film acting credit was Tragic Love (1909).
As far as sci fi genre films, Hatton was in Roger Corman's post atomic holocaust flick The Day the World Ended. He played Pete, an old prospector who brings his donkey into the film's radiation free zone after an atomic war.
Besides quite a few credits in low budget westerns, Hatton had a long career in television. He played The Mole in the Dick Tracy TV series in 1950. Other programs he worked on in a number of roles for each series included The Adventures of Superman, The Cisco Kid, Maverick and many more.
His final role was in In Cold Blood, as a hitchiker.
Hatton passed away in 1971, 5 days after his wife had passed from this mortal coil.