In "Cairo Spooky" (the movie-within-the-episode), John Cena plays Tate Blizzard and Italia Ricci plays Dr. Trish Cavanaugh. As John and Italia's names appear in the episode itself, both on the theater marquee and in the "Cairo Spooky" end credits, they can be considered as appearing as themselves playing their "Cairo Spooky" character. John also appears as himself outside of the movie, too.
At the start of "Cairo Spooky" (the movie-within-the-episode) is the credit "Gordon 3000 Presents". Gordon 3000 Industries is the company that actually produces True Jackson, VP.