Three simple games we have used in the past. Have seen versions of these played everywhere; therefore, they were probably all stolen from Jesus or Peter originally.
Bloody Marshmallows
After shooting ping pong balls into buckets to see which topping they get to use (Bucket marked 1 is Ketchup, 2 is mustard, 3 mayo, 4 Catalina Dressing, 5 Mixture), contestants have 30 seconds to cram as many marshmallows dipped in (condiment) into their mouths as possible. Afterwards, they spit them out and count. I have had a person concerned with this one about it being a choking hazard. You can modify it to make it safer by having them eat each one and count as they go.
Cheerio Shaving
After getting a facefull of whipped cream, students dip their face in a bowl of cheerios. Their partner sqirts of the cheerios with a tiny squirt gun.
Diaper Licking
Students race to see who can lick all the hersheys syrup and candy bars out of their diaper.