The Gymanimals (Thanks, HJE-Cobra!)
Childhood obesity is a bad thing. OK, Gymanimals, we can agree on that. But childhood ignorance is a bad thing, too, so with no shortage of "get healthy, kids!" messengers available, parents probably shouldn't settle for this site:
In case you assumed The Gymanimals © wrote "o-bee-sity" like that just because they spell everything the stupid way, let me introduce you to "the supreme fat lord of the universe," O-Bee-Sity. While the ridiculous name suggests a fat anthropomorphic bee, this "villian" is instead some sort of snowman-shaped blob of stomach bile.
In addition to rampant grammatical errors and disgustingly ugly characters, this site confronts you with a loud, looping clip from "Whip My Hair." (I guess hair-whipping burns some calories, but, again, kids could do better.) You can silence it by clicking "Stop Sounds," but it comes back after like 15 seconds. Fair warning; now here's the link.