If you're in the Multiverse Group, you can use the Adventurer badge on your profile.
- Join the Group. Go here if you're not in the group ---> Multiverse Group.
- Go to your Profile Settings.
- Under Group Title, choose Adventurer.
If you're a Multiverse DM, you can get the DM badge, using the same process. Except, you must be in the DM group.