To join/create a Team you must first build the "Team Zeppelin" that is unlocked at level 16.

To create a Team, follow the steps below:
  • Tap "Create Team" in the Zeppelin
  • Choose the Team Name, Description and rule
  • Tap on Create at bottom of the page
  • You will need 10M Gold to create a Team
To join a Team, you need to have enough "Monster Power" & level set by that Team. You can search for any Team as long as it is an Open Team. To join a Private Team, you need to be invited.
You can also ask your friends for a Team name or join one that you think you can provide help for.