The toys are similar to the Busy Poppin' Pals line made by Playskool, which features characters that pop out of doors when a button is pressed or a switch is pulled. Playskool's line included Sesame versions from 1980 to 2000.
Fisher-Price's first Sesame Pop-Up Pals toy was Talking Pop Up Pals in 1995. This toy has figures of Sesame characters popping up out of doors, surrounded by plastic balls. Each character says a different phrase -- Elmo says "Peekaboo!", Cookie Monster says "Hello!", Big Bird says "Surprise!" and Zoe says "I'm Zoe!"
This was followed in 2002 by Singing Pop-Up Pals. On this toy, pressing a button makes the characters sing -- Oscar the Grouch sings "I Love Trash", Elmo sings "Elmo's Song", Ernie sings "Rubber Duckie", and Cookie Monster sings "C is for Cookie". Another version was produced in 2005 with the same characters popping out of a three-dimensional version of the Sesame Street set.