In order to unlock this achievement, you will need a second controller and another account, then you will need to follow the steps below:
1. Create a public Tumble match (preferably keeping the settings default)
2. Login the second account and once joining immediately start the game by pressing
on both controllers so others don’t join
3. Kill yourself for two rounds using the first account.
4. Kill yourself using the second account three times.
5. Wait ‘till you respawn in the lobby, press
to close the stats menu and...
6. Achievement unlocked. Enjoy.
Here’s a video: