Eelek was a seemingly high-ranking member of Gond society.
After the Second Doctor, Jamie and Zoe presented evidence that the Krotons were manipulating the Gonds, and probably killing all the smartest members of society, Eelek realised there was an opportunity to manoeuvre for power. He advocated full-scale war against the Krotons. Toward this end, he tried to enlist the weapons-making services of the scientist Beta, while simultaneously deposing Selris. Beta, however, favoured Selris' plan of a more subtle, focused attack, which largely left Eelek without the capacity to mount a sustained military campaign.
Eelek then switched to a diplomatic assault, offering to allow two "high brains" to power the Krotons' ship in exchange for their departure. This plan backfired, however, when Beta, Thara, Selris and the TARDIS crew were able to destroy the Krotons without having to sacrifice any more Gonds. Eelek subsequently lost his bid for power to Thara. (TV: The Krotons)