King of Avalon almost always has one or two seasonal events being active. At this time the Appetite for Destruction Event is one of them. This guide explains how the event works.
During the duration of the event you receive Wooden Mallets when you kill monsters and rally barbarian camps, and Crop Beetles when you harvest the resource in your resource buildings. These can be synthesized into Beetle Juice, which can be used for rewards.
You can get Wooden Mallets by killing monsters and successfully rallying barbarian camps. So far I typically only got 1 Wooden Mallet each time I kill a high level monster or rally a high level barbarian camp. I have not tried lower level monsters/barbarian camps.
You get Crop Beetles when harvesting your resource buildings.
You can Synthesize 3 Crop Beetles and 1 Wooden Mallet to one Beetle Juice item.
You get your prizes by selecting the Beetle Juice items in your items and clicking Use. Prizes I have received include: Gold, 100 Dragon EXP, Intensity Crystal (I), 10 Assault Power, 30m VIP, 100 Dragon Spirit EXP, 1K Food, 1K Wood, 200 Iron, 50 Silver, Knucklebone, 5m Speedup, 60m Speedup, 2h Firm Defense, Cerussite, Bronze, Pine, Emerald, Spider Silk, Soul Clay, Sentinel Gem (I), Stallion Stone (I), Refining Stone (I).
There is not much to it, just do what you normally do and collect the extra prizes, the same as several seasonal events before. If you have any questions, or comments, let me know in the comment section.