Rockin' Ricky Rialto was a popular disc jockey heard on the radio in the small town of Kingston Falls. He was one the air the night when malevolent green monsters, known as Gremlins, wrecked havoc on the town.
At first, Rockin' Ricky did not believe the calls he got to his radio station about the Gremlins. He asked his listeners to knock off the "Orson Wells crap." Shortly after he said this, a Gremlin invaded his station and attacked him on the air.
Rockin' Ricky survived the attack and managed to keep himself on the air, providing encouragement for the surviving residents of Kingston Falls. At one point, he assured them that the National Guard was getting ready to attack the creatures with fire hoses. (He had no way of knowing that the Gremlins multiply with water.)
Fortunately for Rockin' Ricky and the rest of the town, the Gremlin threat was ended by that morning.
Rockin' Ricky is never seen throughout the movie, but his voice is heard on various radios. A likeness of him can be seen on a billboard, dressed like Indiana Jones and wielding a microphone like a bullwhip.