Ha-Ha

 was a member of the punishment platoon on Hedgewick's World of Wonders.

He yelled at an attacking Cyberman that he wasn't afraid of it to get attention, and Clara shot it down with an anti-Cyberman weapon. When two partially converted humans began approaching Clara, she threatened to shoot, but Ha-Ha explained that the hand pulses could deactivate them just fine. He was almost upgraded by the Cybermen, but was saved at the last second by the Eleventh Doctor, who froze the Cybermen temporarily. Ha-Ha was then teleported off of the planet with the rest of the survivors by Porridge's ship. (TV: Nightmare in Silver)