He is the Radiskull. He will kill us one by one. Or so says this disembodied, toothsome skull. Radiskull and his sidekick, Devil Doll, are the animated stars of joesparks.com , the product of Flash artist Joe Sparks’s fertile imagination. Each episode of Radiskull and Devil Doll features the duo rapping to a heavy-metal beat and lamenting such evils as snow, fruit, and happy. Radiskull, in his own vernacular, “hate happy.” But Sparks offers more than a fun Flash cartoon land. He dedicates several pages to production notes, detailing the hows and whys of Radiskull, along with shots of his Mac workstations. Sparks also offers Flash tricks and tips, such as how to generate 3-D landscapes. Radiskull may not care for any of this — he “hate happy,” after all — but that doesn’t mean you won’t get a kick out of it.