I have a couple of ideas, but neither the time nor ability to pull them off. Be warned the cuteness is on overload with #1.
1. A baby in either a diaper or gorilla suit, climbing a lego version of the Empire State Building(complete with a mobile of planes for the spire), while holding his sister's barbie doll.
2. Smaug surrounded by his horde of gold with randomly strewn remnants of clothing from the recently consumed dwarves and hobbit. He would be lounging, with an arm behind his head and a sword in his other hand being used as a toothpick. He would have a classic Kawaii smile, to fit in with the theme.
The second idea is pretty similar to one done by Patrickspens a while ago.