Ben and Rook are shown together in Ben 10: Omniverse , which first aired in 2012. The series runs from 2012 to 2014 and is the show where Rook is introduced as Ben’s partner.

Quick Scoop

  • Show: Ben 10: Omniverse.
  • First airing: 2012.
  • Ben and Rook together: from the start of that series, with Rook as Ben’s new sidekick.

If you meant their first episode together , that would be in the early episodes of Ben 10: Omniverse rather than the earlier Ben 10 shows.