I'm not sure about the first image, but the second is called "The Meat Viking vs The Flame King" and was made by "flip" for a Burger King art show. Lots of swell art in his Flickr gallery, including this custom Plushform:
Here's his site, OhNo!Doom. And here's the OhNo!Doom webstore.
UPDATE: The first head is by Tewz. Thanks Ryan.
*Previously: Psychedelic love from the vintage Burger King.
*Find Happy Meal and cereal toys at eBay.