According to one account, the Meeps' home planet "basked" in the light of a "living sun". One "terrible day", this star went "mad", turning into a psychedelic sun which could induce solar psychedelia. (TV: The Star Beast [+]Russell T Davies, adapted from Doctor Who and the Star Beast (Pat Mills and John Wagner), Doctor Who 60th Anniversary Specials (BBC One and Disney+, 2023).)
According to other accounts, the sun which was responsible for the Meeps' turn to warfare and wanton cruelty was the Black Sun into whose orbit their planet had drifted, rather than their own, original sun gone mad. (COMIC: Doctor Who and the Star Beast [+]Pat Mills and John Wagner, DWM Comics (Marvel Comics, 1980).)