Defeat of the Headless Horseman event

After defeating the headless horseman you are able to summon a Nightmare Horse for 8 hours once per long rest. You must use an action to summon it, unlike normal Nighmare summons you do not need a sacerfice to keep the Nightmare loyal to you. Because of the nature you have been given this summons your Nightmare is unable to use Ethereal Stride.

You may summon the Nightmare during battle and use it to excape (given there is room). You can only summon the Nightmare within an open 10ft of you. Doing so gives you the ability to use the Nightmare as a mount during that time.