Karim Zeroual (in-universe)

Karim Zeroual once entered the Twelfth Doctor's TARDIS with Hacker the Dog when they were on a mission to build a robot. (TV: The Robot Reveal)

Biography
Karim and Hacker had a lot of robot designs on a table, one of which they needed to turn into a robot. Karim didn't know what to do with them all, so Hacker borrowed the Doctor's TARDIS, who created BI1nk Bot 3 for them. He and Hacker chased the robot around a bit. (TV: The Robot Reveal)

Behind the scenes
Karim Zeroual played himself in the story.