Untappd is currently running a badge design contest, so if you are a creative type I recommend you enter now! This is the second badge made available as part of the 10th anniversary celebrations, separate to I Remember My First Check-In.
The badge itself is for the 10th Anniversary Party, which is scheduled to be held online on 24 October between 3PM and 6PM ET. The badge itself will only be able to be earnt between those times, so it will be one of the more exclusive badges around.
Untappd Badges 