(Copied from wowhead)
I would like to confirm (since I haven't seen it stated here) that you do
not need to rank up in the Brawler's Guild in order to acquire Meatball -- only completing the missions (with bonus) is required, and the missions will spawn regardless of your rank. My main is Rank 2 and all my alts are Rank 1, but I have Meatball on every character.
In fact, here's a minimal-effort guide for those who want the champion, but don't want to brawl:
- Get a Brawler’s Guild invitation on one character. It works account-wide.
- Defeat Oso. (Yes, one brawl is required.)
- Complete the mission (100% is good enough) There is no Brawlers Guild.
- Watch five wins at the Brawler’s Guild. Turn in quest.
- Complete the missions (you need the bonus loot, so try for 200%) Council of War, Its Clean Up Time, Master of Shadows, and I’ve Got a Strange Feeling About This.
- Turn in the related quest. Repeat Step 5 and 6 for each of the four missions listed.
- Once you've turned in I’ve Got a Strange Feeling About This, enjoy your new champion!
- Repeat Steps 2 through 7 for each character on which you want Meatball.