'Wild Wild West's Arliss Loveless's giant steampunk spider contraption could be the basis for a live-action 'Spydor', while the troll from 'The Lord of the Rings: TFOTR' seems the perfect model for a shadow-beast. Repaint the Star Wars' saga's Naboo a lovely brick-pink and you have Eternia.
Any other existing movie phenomena you could see as the way MOTU movie effects/creatures/environs might go?