(For some who may have not known,before Richard Hortvitz officially became the voice of Zim in the Invader Zim series once it released,when the series was still in development with Nickelodeon,The series creator "Jhonen Vasquez"originally considering Mark Hamil (Or as he's more well known roles as Lyke Skywalker and The Joker) to be the VA for Zim except it was later changed to Billy West in the unaired pilot before Hortvitz in the full show because he considered his voice would have made the character sound older than he should altough the voice actually kinda fits well once I heard it but I think it would fit better for an older version of him)