WoW Heirlooms — Browse All Heirlooms
Track your World of Warcraft heirloom collection. Browse all 134 heirlooms with vendor locations, costs, and upgrade levels. Filter by armor slot and weapon type.
Browse all WoW heirlooms with upgrade levels and acquisition sources. Find heirlooms from vendors, achievements, and special events. Track which heirlooms you own and their upgrade status via Battle.net.
Defending Champion
Source: World Event: Gurubashi Arena.
The 
Defending Champion heirloom is obtained by looting the Gurubashi Arena chest a 13th time on a character that has already earned the 
Arena Grand Master trinket through 12 previous chest openings.
Win 12 Arena Chests
Loot the Gurubashi Arena chest 12 times to earn the Arena Grand Master trinket and its associated achievement. This must be done on the character you intend to receive the Defending Champion heirloom on, as the heirloom is character-specific.
Keep Arena Grand Master
Keep the Arena Grand Master trinket in your bags or bank before looting the chest a 13th time, as not having it in your possession may prevent the heirloom from dropping.
Loot the 13th Chest
Open the Gurubashi Arena chest a 13th time — do not use autoloot if you wish to leave the green Arena Master trinket for other players — and the Defending Champion heirloom will be included in the chest's loot alongside the normal rewards.
Tips
If you looted the 13th chest and did not receive the heirloom, a GM may be able to award it to you if you met the loot requirements at the time.