Help me brainstorm my ToyBox?

In real life, I'm building a Disney themed model railroad that's turned into a physical Infinity toybox, with the additions of Mike and Sulley and Timon and Pumbaa. I know that's how I'm starting the digital version, with Radiator Springs and a close attempt at Woody's Roundup to mirror the layout. I've decided after seeing Rex trapped at Sid's house in TS3 that he needs to stretch his legs. With this said, I want a place that's true to character. What should that be?

Something that feels prehistoric. Maybe a jungle and oil swamps.

[Jbot123]

Volcanoes, trees, and other creatures. Maybe a large habitat are filled with Disney animals. (I think you'll have to wait until the Toy Story playset to unlock Rex)

REX!
REX EVERYWHERE!

Also Ralph and Woody.

I wonder if you'd be able to make it feel like a child's room, or have large toy building blocks. Kind of like directly visiting a toy land and Rex could be the guide.

Why stop at just 1 Rex?

Because I only need one. More than one may makre him feel akward...