She was billed as “Piggy Lee,” and she is just lip synching, so she didn’t get her iconic voice yet. That would take until The Muppet Show in 1976. Originally, Frank Oz and Richard Hunt shared voicing her on The Muppet Show with two different voices because she didn’t start out as a main character (Oz was mostly supposed to voice Fozzie Bear), but Henson and Company realized that Piggy had more star potential than Fozzie and gave it to Frank full-time.
Piggy is currently voiced by Eric Jacobson, who has been doing the voice since 2001, meaning he and Frank have done the voice for almost an equal amount of time at this point.
Eric himself was already a veteran Muppet performer by that point, having begun on Sesame Street in 1994 subbing for Oz as Grover and Bert when Oz wasn’t available. He says he was inspired to become a puppeteer in college when Jim Henson died.
As for Piggy herself? Her creation was a collaborative effort, as were most things at Henson studios when Jim was running things. Bonnie Erickson should be credited with actually designing and creating the original puppet, but Jim came up with the idea (he apparently gave the task of creation to Bonnie, because her uncle had a pig farm in Minnesota) and, of course, Frank gave her the personality we’ve come to love.
Bonnie said that the puppets she was most proud of creating were Statler and Waldorf, but there is no doubt in my mind that she will be most remembered (and hopefully she will be remembered) as the creator of Miss Piggy. Here they are together:
And here she is many years before with the man who started it all-