At the Ogrebane Arena in Kaladim is where "The Klaw" appears for this quest.
I didnt find much info on this ring event, so... from what I can tell:
- When it's ready, there will be a Ringmaster (non-attackable) up top, overlooking the arena, and some fighting bugbears and kobolds in the pit (also non-attackable).
- Around the edge are some wandering gnolls and spectators. Kill the spectators to begin the event.
- Once you've killed the spectators, the fighters in the pit become attackable - So... kill them :)
(You can kill the wandering gnolls too, but it didnt seem to matter - I cleared the entire event without touching them once).
- Once the 2 groups in the pit are dealt with... a more difficult named will spawn. I did the event 4 times, and 3 of those times produced a goblin called "The Master Miner". The 4th time, however, spawned "The Klaw".
- Once you kill The Klaw or the Master Miner, the Ringmaster will come down and attack you. Kill him to complete the event.