Robot Knight

The Robot Knight was a robot created by the Sontaran Jingo Linx.

History
The Robot Knight was made from a knight's armour and given to Irongron as a gift. It was activated by remote control.

Irongron used the Knight to attack Hal the archer, who had become a prisoner during a failed assassination attempt on Irongron. However, the Third Doctor used a crossbow to shoot the control box from Irongron's hand. This caused the Knight to go on a rampage.

Later, the Doctor masqueraded as a Robot Knight in order to gain access to the castle. Irongron requested the Knight to fight him, so the Doctor was forced to take part in a sword battle with Irongron to uphold the disguise. The Doctor won, but Irongron discovered it was him. (TV: The Time Warrior)