Master of Spiders

The Master of Spiders was the supposed ruler of the spiders on an unknown swamp planet.

Biography
The Master of Spiders sought to keep in order his empire of spiders on the unknown planet which he resided on.

When the Second Doctor with John and Gillian arrived on the planet, the Master was spying on them from his giant mechanical spider. He had his spiders pursue the Doctor and his grandchildren into a cave, intially sealing them in 'for eternity'.

However, the Doctor, using his recorder, stopped the spiders from reaching them, whereupon the Master instead released a net on the three, capturing them and pulling them into the air. He then sent his spiders onto the Doctor and his grandchildren. The Doctor used his recorder again to interfere with the device the Master used to control the spiders. The spider attacked the Master.

The Master fled in his mechanical spider as the Doctor and his grandchildren got out of the net. With the Master about to attack them, the Doctor quickly fired his newly built ray gun at the mechanical spider destroying it and presumably killing the Master within. (TVC: Master of Spiders)