The history of the cartoon universe: Mickey's Choo-Choo (1929)

The canonical choice for 1929 would be The Skeleton Dance. But where that cartoon undermines reality the same way as all horror (though it also undermines horror itself through, like, skeleton pogo sticks), Mickey's Choo-Choo undermines (wait for it) perception itself*. Stealing the show from Mickey is his anthropomorphised locomotive: not quite soft architecture, but on the way. Iwerks makes the choo-choo memorably malleable: it moves like an animal, wobbles like a jelly, and generally hams it up. Between this and The Skeleton Dance, Ub and Walt basically achieve what Dali was aiming for, except with more laughs and arguably less kitschiness**.

*yes, I know The Skeleton Dance also undermines perception, just not as much
**though as both Disney and Dali knew, kitsch can be great