A cartoonist and family man, Tim Avery (Jamie Kennedy) lives a peaceful existence with his wife, Tonya (Traylor Howard), as well as their infant son and dog. When the curious canine finds a mask with mystical properties, both dog and baby create chaos with its powers. While Tim and Tonya try to contain the damage, the sly Norse god Loki (Alan Cumming) comes looking for the artifact, resulting in more mishaps that ultimately incur the wrath of the deity's powerful father, Odin (Bob Hoskins).