Your Charisma increases by 2, and Strength by 1.

Due to their undying nature, as long as their bodies are properly preserved, they can live forever. However, after centuries, most Dullahan's bodies decay beyond repair.

Dullahan vary greatly in their size, depending on their original race, but tend to be on the taller side, regardless, your size is Medium.

Your base walking speed is 30 feet.

You can read, and write Common. Dullahan remember the languages they spoke in life, but due to their headlessness, cannot speak unless they don a freshly cut head, or a skull. Sometimes, other objects can suffice; like a pumpkin, carved in the likeness of a face. While wearing another persons head, you can take on their voice and mimic their manner of speach if you have proficiency with Deception.

You have blindsight of 120ft., unless wearing a substitute head, then, due to your eldritch senses being covered, 60ft.

Vulnerable to damage made with gold weapons, due to their purity.

Resistance to Poison and Cold damage.

Your magical undeath renders you immune to magical sleep, and allows your long rest to consist of only of 4 hours, during which you are inactive, but remain conscious. You also do not need to eat, drink, sleep, or breathe.

You can replace your empty neck with a head, skull, or other appendage such as a carved pumpkin, during which you can speak and see as an ordinary creature could, with the cost of your blindsight being reduced.

Typically a replacement head has an Armor Class of 15 plus your Dexterity, and 2d4+2 hp. A creature can target your head instead of you for an attack roll, provided it would reasonably be able to do so. It makes an attack roll against the heads armor class, with disadvantage if you are mounted, and on a hit, deals damage as normal, if the head is reduced to zero hp, it is destroyed, and you lose any benefits from wearing it. Alternatively, a creature can make a Sleight of Hand check against the heads AC, and swipe the head from your shoulder's on success. Attacking the head, deals no damage to you, and if an attack requires a saving throw, you use your saves as normal.

Starting at 3rd level, when you score a critical hit with a melee weapon that deals slashing damage, you can deal 1d8 extra slashing damage, in addition to the normal critical damage. If this damage reduces a creature to 0hp, that creature is decapitated if it has a head or similar appendage. This extra damage increases to 2d8 at 6th level, and continues to increase every 3 levels thereafter.

As an action, you let out a bloodcurdling shriek, all creatures (including allies) in 30ft. must succeed on a WIS save (DC=8+Prof.+CHA), or take 3d10 psychic damage, and be frightened until the end of your next turn, in addition, if this action deals damage to any creature, you gain 10 temporary hp.

Starting at 5th level, as an action you can summon a spectral steed that has the statistics of an unarmored warhorse but is a Fiend or Undead (your choice), that lasts until it drops to 0 hit points, or until you move more that 300ft. away. You are the only one who can ride this horse, others just fall through it as if it were and illusion; however it can still be targeted by attacks and take damage.

Also, you gain proficiency in Vehicles (Land). You can only have one steed at a time.

Once per Long Rest, As a Bonus Action, say the full, proper name of a creature that can hear you in 30ft. That creature must must succeed on a CHA save (DC =8+Prof.+CHA), or be marked for 1d6 rounds, during which, the target is frightened of you, and you have Advantage on attack rolls against it. When you hit that creature with a melee weapon that deals slashing damage, that attack is a critical hit. Additionally, if the target fails, you can sense the targets general direction and position for the next 30 days.

A creature that succeeds this saving throw is immune to it for 24 hours.