The ads featured Onky (a puppet who would go on to become Mack in later ads), with a human grocer played by Bill Gibson. Onky would ride in a shopping cart full of On-Cor Frozen Food products and stop, and say to the viewers "On-Cor! You'll want more! On-Cor Frozen Foods!".
Chicago advertising executive Bill Wright hired Henson to produce the ads. Wright also worked with Henson in representing Kraml Dairy.
- Jim Henson's Red Book entry (1/25/64)