The Vehicle in Scribblenauts is defined by anything Maxwell can ride on or in (that's not alive).
Backhoe
Battleship
Bike
Blimp
Bulldozer
Car
Cherry Picker
Elevator
Escalator
Fighterjet
Ghost Ship
Hang Glider (Vehicle)
Helibackpack
Helicopter
Hot Air Balloons
Hoverboard
Hover Craft
Jet Pack
Lawnmower
Lift
Monster Truck
Motorcycle
Pirate Ship
Pogo Stick
Rally Car
Rickshaw
Rocket Belt
ROFLcopter
Sailboat
Skateboard
Space Shuttle
Stroller
Submarine
Tank
Teleporter
Time Machine
Train
UFO
Unicycle
