Nighttime Scavengers
Before the party begins, hide some tokens in the yard. These could be handmade dolls, small balls or toys. Have a token for each team. Assign the teams colors to represent them. Each team should have a token of the same color hidden in the yard. Give every team one flashlight and a clue to find the whereabouts of their token. If a team finds the token belonging to a competing team, they can steal it. This game is fun when you have several tokens hidden for each team. The team that returns with all or most of their tokens to the host first wins. Do a reconnaissance in your yard during daylight hours to check for potholes or things players could get hurt on.
Feed Me
Play the game four players at a time. Let everyone have a turn or choose a few to represent groups. One person is the feeder and the other is the eater. The eater wears a garbage bag over his clothing to protect him from food stains. In front of him are open bowls of food like ravioli, pudding and gelatin. The second player stands behind the first player. The eater cannot use his hands to pick up the food. The second player wears plastic gloves and shovels the food in the eater's mouth while standing behind him. Use a timer to see which team can eat the most food in a minute. This game is messy but funny to watch.
Balloon Pop
Blow up a bag full of balloons or one for each person before the party. At game time, give everyone a balloon to pop. Give them rules to make it harder. Tell them they cannot use their hands or feet to pop the balloon. Alternatively, make them stuff the balloon in their shirt and pop it. Let four or five people go at once. The first poppers compete at the end with a pop-off finale. Award the winner with funny gifts like a whoopee cushion or another noisemaker.