Equip two of the professional with the different tools. Note that you may have to mix and match between the different occupations for the golden crown. We have not separated out the key items for you.

Cook: Knife, Scissors
Police: Gun, Weapon
Fireman: Hose
Doctor: Notebook, Stethoscope

Scribblenauts Remix 1-2 Cheats Hints gallery:
1-2-1-a: Give two of them what they would use in their hands!
1-2-1-b: Give the chef something he would use in the kitchen.
1-2-1-c: Give the fireman an axe.