Compendium 3 and the Citadel Journals for Spring 1986 & 1987 carried a comic strip with the adventures of Kaleb Daark, the follower of a fifth Chaos God, Malal. What became of Malal? Rumour has it that GW didn't hold the copyright, the artists and writers did. They and GW disagreed on the direction of the storyline and so the strip disappeared along with its God and Heroes.
Kaleb Daark's backstory and stats appear in the Spring 1986 Journal.