Co-op Mission Class Challenges are a class of multiplayer challenge under the Co-op category. Each challenge has a single rank which requires the player to complete all six Co-op missions as a specific playable class. Equivalent challenges are available for normal co-op and advanced co-op, with one additional challenge in advanced co-op to cover the No Holds Barred class.
When each challenge is completed, the player earns XP. Unlike many other challenges, no Titles are earned for co-op challenges.
The challenge title "I'm Your Huckleberry" is a quote from Doc Holliday (played by Val Kilmer) in the 1993 western Tombstone. Holliday makes the statement to the infamous Johnny Ringo, when calling him out to a duel.