Paul Kasey

Paul Kasey is,, the one actor to have appeared the most times in the revived Doctor Who, Torchwood and The Sarah Jane Adventures, aside from each show's regular cast. He has appeared several times in every series of each programme — 32 times total in DW, 13 times in TW and 18 in SJA. He's also featured in behind-the-scenes spin-offs such as Doctor Who Confidential and Totally Doctor Who. When paired with Alan Ruscoe, he can be recognised as the shorter of the two actors.

Doctor Who

 * Auton (TV: Rose)
 * Coffa (member of the Forest of Cheem) (TV: The End of the World)
 * Jocrassa Fel-Fotch Passameer-Day Slitheen and Sip Fel-Fotch Passameer-Day Slitheen (TV: Aliens of London / World War Three)
 * Zu-Zana (TV: Bad Wolf)
 * Control node (TV: The Girl in the Fireplace)
 * Cyber-Leader One, Cyber-Leader Two, Cyber-Controller and Cyber-Lord (TV: Rise of the Cybermen / The Age of Steel, Army of Ghosts / Doomsday, The Next Doctor)
 * Ood (TV: The Impossible Planet / The Satan Pit, Planet of the Ood)
 * Hoix (TV: Love & Monsters)
 * Robot Santas (TV: The Christmas Invasion, The Runaway Bride)
 * Judoon captain (TV: Smith and Jones, The Stolen Earth)
 * Pig slave (TV: Evolution of the Daleks)
 * Host (TV: Voyage of the Damned)
 * Ood Sigma (TV: Planet of the Ood, The Waters of Mars, The End of Time)
 * Hath Peck (TV: The Doctor's Daughter)
 * Sorvin (TV: Planet of the Dead)
 * Judoon captain (TV: The Pandorica Opens)
 * Nephew (TV: The Doctor's Wife)
 * Albert Einstein Ood (TV: Death Is the Only Answer)
 * Wooden Queen (TV: The Doctor, the Widow and the Wardrobe)
 * Time zombie (TV: Journey to the Centre of the TARDIS)
 * Whisper Man (TV: The Name of the Doctor)
 * Zygon (TV: The Day of the Doctor)
 * Footman and the Twelfth Doctor's disguise (DWM) (TV: Deep Breath)

Torchwood

 * Janet (TV: Everything Changes, Day One, Greeks Bearing Gifts, Combat, End of Days, Sleeper, Adam, Reset, Dead Man Walking, A Day in the Death, Exit Wounds)
 * Weevil (TV: Combat, Dead Man Walking, A Day in the Death, Fragments, Exit Wounds)
 * Blowfish (TV: Kiss Kiss, Bang Bang, Fragments)
 * Hoix (TV: Exit Wounds)

The Sarah Jane Adventures

 * Glune Fex Fize Sharlaveer-Slam Slitheen, Kist Magg Thek Lutiven-Day Slitheen and Florm Rox Fey Fenerill-Slam Slitheen (TV: Revenge of the Slitheen)
 * Uvlavad Kudlak, Uvodni Emperor, and The Mistress (TV: Warriors of Kudlak)
 * Dax Fex Fize Slitheen (TV: The Lost Boy)
 * Judoon (TV: Prisoner of the Judoon)
 * The Dark Rider (TV: Mona Lisa's Revenge)
 * Leef Apple Glyn Slitheen-Blathereen (TV: The Gift)
 * Slitheen (TV: The Nightmare Man)
 * Shansheeth (TV: Death of the Doctor)
 * Red Robot (TV: The Empty Planet)
 * Metalkind (TV: Sky)

Other

 * Monster (Doctor Who: A Celebration)

Doctor Who at the Proms

 * Hero Monster (Doctor Who at the Proms (2008))
 * Judoon Captain (Doctor Who at the Proms (2010))
 * Lead Monster (Doctor Who at the Proms (2013))