Lasts for 1 hour, during which every monster can drop candies, which can be traded for rewards to the Fear Mongerer, who appears for 3 hours, appearing an hour before the event and disappearing an hour after the event ends.
When: Every 3 SkyBlock days (every real-life hour).
The Dark Auction is a place where you can bid on exclusive items. It is recommended that you take a lot of Coins though, as the items sold here go for quite a lot.
For a very short amount of time, an NPC called Sirius spawns outside of a house near Tia the Fairy. Speak to him to enter the Dark Auction. The Dark Auction starts at the 55th minute of every real-life hour (e.g. 9:55). It is recommended to have as many coins in your purse as possible to have a higher chance of getting in since only the people with the highest money on them will be let in. There are 4 total bouts of bidding, each for a different item, the last item always being a Flower Minion. You can find a timer on when the event happens here.
While not events per se, certain bosses only appear at specific times: