. "produced a line of Muppet valentine cards from 1990 to 1992. There were two different sets of cards, and a variety of packaging designs, always featuring Kermit the Frog and Miss Piggy."@en . "produced a line of Muppet valentine cards from 1990 to 1992. There were two different sets of cards, and a variety of packaging designs, always featuring Kermit the Frog and Miss Piggy."@en . "Muppet valentines (American Greetings)"@en . .