Slices of bread
This one is best for individuals
This can be done anywhere
As simple as it gets: Bite the best image out of this slice of bread. Players can only "cut" the bread into a shape with their teeth, no tearing or forming with their hands.
Scoring is, as always, completely arbitrary, you can award only the best or award points on a sliding scale from best to worst. Decide how you wish based on the number of players.
If this is too vague of a task, you can ask them to bite out the shape of a famous landmark or a self portrait, really whatever you think your players can handle and will be the funniest.
Gluten-free bread option?