Frogs are amphibians featured in many Muppet productions. The best known Muppet frog is, of course, Kermit. Originally designed as an abstract lizard-like creature in 1955, he was referred to as a frog on several occasions during the late 1960s (including The Muppets on Puppets). In following productions (Hey Cinderella!, Sesame Street), he was given webbed feet and a collar, and referred to as "Kermit the Frog". In 1971, a group of frogs similar to Kermit -- yet without collars and stripes…