Froggy the Gremlin

Froggy the Gremlin was a character created by Smilin' Ed McConnell and brought to radio in the 1940s and television in 1950s on the Smilin' Ed's Gang show, and later Andy's Gang TV show, hosted by actor Andy Devine after McConnell's death.

Disrespectful of adult authority figures, Froggy played practical jokes and disrupted the presentations of other guests.

[1] On radio and the early TV shows, Froggy's voice was frequently supplied by Arch ("Archie") Presby, who was also the program's announcer.

He appeared on screen in a puff of smoke with the catchphrase, "Hiya, kids!

The Search for Smilin' Ed by Kim Deitch, Fantagraphics (2010)