Treasure Bugan Event
Guide: Here are some notes from last year, as well as the current patch notes, for Treasure Bugan. This year it will be 7/21 through 7/25. It is a 5-day event. Upon receiving your first quest (at minimum level 20), you will receive a wrapper quest that requires you to complete the quest 3 times each day for 4 days. There is a 75% chance a little goblin will spawn when someone gets close to the designated location in an instance scaled exactly to your level. The only valid instances will have Theodore at the entrance; you will be able to turn your quest in at any Theodore you encounter. You, as an individual, must get close enough to the bugan to have the quest auto-bestow when it appears. You have 60 seconds to defeat it before it disappears, or it fails the quest. You must wait 5-minutes before obtaining another quest, regardless if you succeed or fail and whether or not one spawns or not. You will normally receive two character-bound coins. The wiki has a list of rewards and locations. Sword Halls is perhaps the easiest as it appears before the fight begins. The "feather" will give you a 100% spawn rate, lasts 90 minutes real-time (no freezing by logging out), and can only be purchased with 10 Mithril Coins.
Rewards: Original rewards are the Teacup and Golden Cave-Claw pets. The backpack must be equipped on-person for the falling coins and sound effects. The event has been updated "with new cosmetics and new LI reward options" in addition to the items available previously. The notes mention a Blood Craban and one of the posters mention seeing something originally contained in Midsummer Festival hobbit presents.