Geltis
From Tardis Wiki, the free Doctor Who reference
Geltis was a nobleman of Solturis and the cousin of Lurr. He offered to give the visiting Daleks the operating key of the Penta Ray, while secretly planning to use the weapon to seize power for himself. When Lurr found out about Geltis's betrayal, Geltis stabbed him and blew up his house. After bringing the key to the Daleks, he turned the Penta Ray against them, but was killed when Jareth threw a rock at him, knocking him over a cliff. (TV21: The Penta Ray Factor)
