How do you get the Pizza Planet truck into a movie set hundreds of years before the invention of the combustible engine? Very, very sneakily.
In the scene in the witch's hut, she is emphatic that she only carves bears...and pizza trucks as you can see in the lower left corner of this screen capture.
During another part of the scene, you can see Sully from Monsters Inc. carved into a slab of wood in the witch's house.