This is a one-on-one game or ice breaker I have used before with fine results, but when I adapted it as a group activity, the roof blew off this sucker. Divide your larger group into smaller groups, it’s best to do 3+, but it can be done with pairs. The rules are as follows:

Sumo Wrestlers beat Robots (obviously)
Robots beat Ninjas (debatable)
Ninja beats Sumo Wrestler (you can make up theories as to why)

The groups will face off against each other by, on the count of three, two groups will rush into the arena, aka your designated area, and in unison they form the shape of their choice. Winners move on, loser sits out. Sumo Wrestlers form the squat, sumo wrestler form. Robots do the Robot (dance move). Ninjas get to pick any fighting, ninja-like stance. The whole team must be displaying the same choice or they lose automatically. Continue rounds until only one team is left. In the event of a tie, both teams remain.
This is a fun way to act silly, get to know a smaller group of people, and fill some time. I like to use these groups for other parts of the meeting as discussion groups or teams for other activities to help solidify budding connections formed by acting like a sumo wrestler and dancing like a robot.
You can replace any or all of the characters, just make a trio of different people or characters that your groups can imitate and a hierarchy to the characters and have fun!
Go get’em, Tiger.