As your best guesses and Photoshop efforts had already worked out, the upcoming Scribblenauts Unlimited will feature cameos from some of Nintendo's biggest stars, including Mario, Link, Zelda and Luigi.
The Week In Games: System Shock, Street Fighter 6, And More
Weirdly, these characters will only be available in the Wii U version of the game, not the 3DS edition. And what's more, you won't be able to run them through the editor, either.
Maybe the handheld will get its own exclusive characters?