Hi Stumbler! Inferno Dragon here to assist you with any gameplay & feature related FAQ. 🐲 
 
You can change your in-game user name (nickname) by clicking your Stumbler avatar from the home screen, then clicking the pencil icon beside the nickname.
Since we’re at it, why don’t we change our profile name? The first name change is free, then the next name changes after that will cost you 100 Gems each.
Make sure to check if your picked name is already taken and the character limit (4-12 characters long).
 
Have a scorching day!