The Mekon was a space-travelling Venusian criminal and an enemy of Dan Dare. He appeared as a short humanoid with green skin and a humongous, bold cranium. Dare once described him as "the stingiest, most hard-boiled egghead in the galaxy". (COMIC: Comic Relief Comic)
The Mekon and a platoon of henchfolk of his, as well as a Dalek, Ice Warrior, Cyberman and Draconian, were present on a Treen colony when Dan Dare and Digby collected funds for a charity from the Treens in 1991.
Before they could cause any harm, however, several incarnations of the Doctor used a special device to propel artificial "red noses" filled with concentrated kindness at the troublemakers. Humiliated and mellowed, the Mekon was pressured to give some money to the charity himself. (COMIC: Comic Relief Comic)
The Mekon and his enmity with Dan Dare was documented in the British children's comic Eagle as early as April 1963, when Susan Foreman's classmate Gillian Roberts compared John Brent to him, giving him the nickname "the Martian," in spite of the fact that the Mekon was Venusian. (PROSE: Time and Relative)