I Know Simpsons Episode "Who Shot Mr. Burns?" is a Two-Part Interactive Episode, Tying together TV and Internet, with the internet tells who shot Mr. Burns, like Maggie Simpson, Moe Syzlak, Sideshow Mel, Homer Simpsons or Seymour Skinner. at the end, is reveal that is MAGGIE SIMPSON.
"Where's Perry?" could be similar to "Who Shot Mr. Burns?" like Telling, Where's Perry, with a laser hitted him? . If is True. This could be the first Phineas and Ferb episode, tying together TV and Internet.