Muzzle Run currently has three collections (Breeder Collection, Racer Collection and Rabbit Collection) and each collection contains a subset of subcollections (Common, Rare, Very Rare and Extremely Rare). Muzzle Run incentivises players who manage to own entire collections and subcollections with free tournaments awarding Matic prizes.
View which cards you have collected and still need to collect from the Collections tab.
You do not need to own a Racer of every generation to be considered to own an entire collection. For example, if you own an "Allan" with box preference 1 you do not need to collect any other Allans with different box preferences to complete your collection.
There are ongoing tournaments for kennels who manage to collect different collections and subcollections. View the tournament tab to see what's running next.
The user below needs to own an Andrew Racer with any shirt number (generation/box preference) to own the entire Very Rare subcollection.