Before the party, mark two goal lines across from each other using string or masking tape.
The goal lines should be fairly close together (i.e. no more than 20 feet apart).
At the Party:
At the party, divide the children into two even teams; one team should be the "Blue Crabs" and the other team should be the "King Crabs."
Have half of each team line up behind the starting line and the other half line up behind the opposing line, then demonstrate the "crab walk" for them (i.e. walking on your hands and feet with your belly up).
To start, the first child on each team gets into position on the starting line.
When you say, "Go!" each child should crab walk to the opposing line and tag the next player on his or her team.
The next player then crab walks back to the start line, tags a teammate, and so on until one team's last player has crossed the line and won the game.