What's 80's sci fi fantasy that has a bullied boy who travels toa cartoon world by a tlkin red car where there's a tlkin dog black slime creatures a wizard who conducts weather n weird things ASAP?

What's 80's sci fi fantasy that has a bullied boy who travels toa cartoon world by a tlkin red car where there's a tlkin dog black slime creatures a wizard who conducts weather n weird things ASAP?
The Phantom Tollbooth