I’ve been thinking about that Grinch movie idea and little bits of dialogue have been popping into my brain, and I’m pretty sure I’d have at least one small line where the Grinch references his “cousin Onceler,” just to canonize the “The Onceler and the Grinch are the same species” idea.
OOO! OOOOO! And the Cat in the Hat could be Cat Z, the infinitesimally small Cat in the Hat from The Cat in the Hat Comes Back! Because Whoville exists on a speck of dust, so it would follow that its Cat in the Hat must be the super tiny cat!