Chuck the Chicken
This game is difficult to explain, but a lot of fun to play. It is likely THE original Chicken Game.
Split your players into two teams. The goal of the game is to earn your team points, however, earning points takes a lot of work!
Team A starts off with possession of the rubber chicken. They form a line and pass the chicken from the back of their line to the front in the following manner - through the legs of the second-last person in line, then over the head of the next person, then through the legs of the next person, and so on.
Team B starts off by scrunching themselves into the smallest human 'knot' possible, all except for one player on the team. This player needs to run around and around the outside of the clump of Team B players. For each full circuit of the clump, the team earns one point.
When the chicken reaches the front of the line of Team A, the person at the front of the line yells "CHUCK THE CHICKEN!" as loud as they can and throws the chicken as far away as possible. Team A then immediately forms into a clump and one person starts to run laps around the clump, earning Team A points.
When Team B hears Team A yell "CHUCK THE CHICKEN", they immediately break off from their point-gathering and run to wherever the chicken has landed. They form a line like Team A did at the beginning of the game and pass the chicken up the line - under one person's legs, over the next person's head, under legs, etc. When the chicken reaches the front of the line, the leader yells "CHUCK THE CHICKEN!", throws the chicken away, and Team B goes back to the clump formation to keep adding points to their score.
This craziness continues for as many rounds as you like - or until everyone is so exhausted that you have to stop. Just ensure that each team gets an equal number of opportunities to gain points. At the end of the game, whichever team has more points wins!