Everyone is it
If none wants the be catcher, or too many wants, you can let everyone be both catcher and they also have to avoid being caught themselves.
You catch someone by touching another. The last one untouched wins.
The participants spreads out before start. If anyone touches you with the hand, you have to stand still. You can still touch anyone else getting within reach (both legs must stay fixed on the ground).
If to participants touches at the same time, nothing happens, you should “neutral” and goes on. If “neutral” you are not allowed to catch the other one at once.
The game end as it requires a lot of awareness to both avoid being tagged, and tag someone else.
To avoid cheating you could rule that all non-tagged, should stay in movement, as you could otherwise play tagged until everyone else has been tagged. In the normal game that can be the tactical way of winning.