The Headless Horseman in Dragon's Dogma 2 is a random rare spawn boss that will appear at night. Not only will it drop Cursed Dullahan Bones when you defeat it, but you’ll also unlock the ‘Before Dawn Breaks’ achievement too.

Now, the hard part here is actually finding one to come across. In fact, it took more than 50-hours for us to come across one, and the only reason we did was because we were stranded in the woods at night after our oxcart was destroyed by an Ogre.

That said, there are a couple of forced appearances of the Headless Horseman, so don’t worry too much.

The first is during the side quest, “Til Death Do Us Part,” which you can get from Margit in the Noble Quarter of Vernworth - provided you’ve finished “The Nameless Village,” not finished “Feast of Deception,” and also heard the rumour of Ser Rudolph from the messenger in Vernworth.

We also encountered one every time on the road north of Vernworth while in the Unmoored World, just by the bridge that leads over the river and into the Elven territory.

Simply defeat the Headless Horseman - it’s not too difficult to beat - and the ‘Before Dawn Breaks’ achievement is all yours.