Contain the bear in the ditch and replace the camper’s gear.

First, equip Maxwell with a flying device and lure the bear to the ditch. Then, replace camper’s gear.

Round 1:
Flying device: Wings
Camper’s gear: Sleeping bag and tent

Round 2:
Flying device: Flying Shoe
Camper’s gear: Flashlight and Grill

Round 3:
Flying device: Jet Pack
Camper’s gear: Lantern and Blanket

Alternatively, you can move around a “force field” to push to bear into the ditch easily.

Scribblenauts Remix 12-4 Cheats Hints gallery:
12-4-1-a: Contain the bear in the ditch and replace the camper’s gear!
12-4-1-b: Lure the bear with food.
12-4-1-c: Replace the camper’s sleeping equipment.