Hey guys, I'll be honest in that I know nothing about converting monster races into player races. the monster I've always wanted to play as since I've started playing was a Dullahan.
Heres the info on a Dullahan.
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Dullahan CR 7
XP 3,200
LE Medium undead
Init +2; Senses blindsight 60 ft.; Perception +16
Aura frightful presence (30 ft., DC 19)
DEFENSE
AC 21, touch 11, flat-footed 20 (+10 armor, +1 Dex)
hp 85 (10d8+40); fast healing 5
Fort +7, Ref +5, Will +12
Defensive Abilities channel resistance +4; Immune undead traits; SR 18
OFFENSE
Speed 30 ft. (20 ft. in armor)
Melee +1 keen longsword +14/+9 (1d8+6/17–20 plus 1d6 cold)
Special Attacks chilling blade, death’s calling, summon mount
STATISTICS
Str 20, Dex 14, Con --, Int 14, Wis 16, Cha 18
Base Atk +7; CMB +12; CMD 24
Feats Iron Will, Mounted Combat, Ride-By Attack, Trample, Weapon Focus (longsword)
Skills Handle Animal +14, Intimidate +17, Perception +16, Ride +7, Spellcraft +15, Stealth +10
Languages Common, Sylvan
SPECIAL ABILITIES
Chilling Blade (Su)
A dullahan is proficient with all simple and martial slashing weapons. When it wields a slashing weapon, the blade inflicts +1d6 cold damage and gains the keen weapon property.
Death’s Calling (Su)
Once per day as a standard action, a dullahan may place death’s calling on a target within 60 feet (DC 22 Fortitude negates). If the dullahan knows and speaks the target’s name, the target takes a –2 penalty on the save. If the victim fails the save, he becomes staggered for 1d6 rounds. For the next 24 hours (or until the dullahan is slain), all critical hits against the victim automatically confirm. Finally, the victim automatically fails all Constitution checks to stabilize while dying. This is a mind-affecting curse effect. The save DC is Charisma-based.
Summon Mount (Su)
As a standard action, a dullahan can summon a war-trained heavy horse with the fiendish creature simple template. This horse remains until it is slain or the dullahan dismisses it. He can only have one such horse in his service at a time.
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So guys, do you think its doable? and would you mind helping me do it?
Since a dullahan is an intelligent undead (i.e., not mindless), you could just treat it as if the base creature is equivalent to a 8th-, 9th-, or 10th-level character (depending on how powerful you feel their abilities are in relation to other PCs; the fast healing 5, plus undead immunities and other abilities, would skew me toward 9th- or 10th-level personally). Then add regular class levels.
Granted, it only works with a high-level game, but with Holloween coming up a "monster" party (flesh golems, lycanthropes, and undead... oh, my!) could make a nice one-shot.
Halloween themed "monster" party:
Awakened flesh golem magus 5 (shocking grasp for self-healing...)
Dullahan warpriest 5
Green hag witch 7 (there just has to be a witch, after all...)
Natural werewolf mesmerist 11 (psychic spells can be cast in animal form, as well as humanoid and hybrid forms...)
As to why the group above would work together, make the magus a hex magus (Coven and Flight hexes), the witch a gravewalker, and the mesmerist with VMC witch (taking Coven as the hex at 7th level). The golem, green hag, an werewolf are a coven, while the dullahan is allied with the coven (possibly created by a previous, more powerful, member and made an agreement to serve?).
Step 1:
Ignore the monster statblock. if you want to play as a Dullahan you still have to adhere to the rules and systems players make and play their characters by, Headless horsemen can have all sorts of fighting styles depending on your vision of them.
Ive seen a headless horseman that held back and threw flaming skulls at people (could be any caster or even a kineticist).
Ive seen a headless horseman that fought nobly (Paladin, cavalier, whatever).
I´ve seen headless horsemen that revelled in causing fear and confusion (Again, caster).
The coolest dullahan I ever saw wielded a black scythe made of shadows and rode a motorcycle.
Once you've decided exactly what kind of headless horseman you want to play start figuring out what makes a headless horseman interesting to you.
Do you want to fool around with the detatched head, perhaps even leaving it lying around?
Do you want to have some magical mount unique to yourself?
Do you want to be undead or fey?
If I were the GM I would suggest you play it as a homebrew race with the following abilities:
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Fey Humanoid.
Abilities: Str +2, Con -2, Wis +2.
Low light vision.
Eerie: You take a -2 penalty on diplomacy and bluff checks, the penalty is trippled while your head is unattached.
Detached head: Your head can be detached from your neck, detaching the head is an immediate action but reattaching it is a standard action. Your ability to sense your surroundings is unchanged when your head is unattached, however you are able to sense your surroundings from both your head and your main body simultaniously, whilst unattached you can speak from your body with a whispy magical voice, or your heads mouth, or both simultaniously. If you are ever further from your head than 1000 feet or on a different plane of existence the head closes its eyes and mouth and falls asleep, severing the sense link between head and body.
Your severed head has all of your applicable defenses and resistances, your head has 1/4th of your hitpoint total, damage dealt to the head while detached is dealt to the body as well (Damage dealt to Head and body simultaniously (Such as area spells) is not transfered in this manner).
If your head is destroyed it reappears in your arms one week later, If your head remains unattached for one week it instantly reappears in your arms.
Cleave free: When you suffer a critical hit there is a 10% chance that your head is immediately detached from your body, when this happens the damage of that critical hit is reduced by half.
At-will Spell like ability: Mount.
Spectral horse: The mount conjured by your spell like ability is bound to your soul, the mount is immaterial and cannot be ridden by anyone but you nor can it affect or manipulate its surroundings. Your mount lasts as long as you remain awake, if the mount passes out of your field of view it winks out of existence. At 5th character level your mount can support up to one additional passenger while you ride it, if you permit.
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Thats a wall of text, but it should work for nearly any class you want to play it as.