Half Demon (3.5e Template)
From D&D Wiki
Half demons look much like a member of the race its humanoid parent belongs to. A notable exception is the pure white hair that is a shared trait among those of the Half Demon type. When transformed their white hair stands up in a multitude of spikes and their skin turns a pitch black. Any cloths or armor they are wearing at the time take on a Demonic look and seem to fuse with their bodies. They are also surrounded by a twisting and burning aura of blood red demonic energy. They sprout bat-like wings which allow them to fly.
Creating a Half Demon
Half Demon is an inherited template that can be added to any living, corporeal creature with an Intelligence score of 4 or more.
Size and Type
Half Demons have the extraordinary ability to bring the power of their demonic heritage to bear on their opponents. This transformation can be used as a swift action to change between forms at will and cannot be suppressed by any means short of unconsciousness. This is because humanoid creatures cannot handle such an influx of energy; it is too powerful, and such demonic energy clashes with the nature of humanoids. As such, for every round the Half Demon remains in this form, it takes 1d4 points of damage on its turn before it acts. While in this form, Half Demons gain +10 Strength, +10 Constitution, +10 Dexterity, +30 Intimidate bonuses and Times 2 Movement Speed on ground. They can also fly with perfect maneuverability. While in this form, the half demon flies into a rage of sorts, attacking any threats relentlessly and without mercy. The half demon will not attack his comrades. While in demon form, any divine magic a half demon uses changes into pure demonic energy from the lower planes.
Special circumstances: When the half demon's hp drops to 25% or lower, the half demon has a 80% chance of involuntarily changing form. The player does not take the 1d4 damage when this is activated.
The Half Demons base land speed is the same as the base creature. If wings 60ft fly speed + base creature if applicable
Half Demons gain a +6 Natural Armor
Half Demons retain all the attacks of the base creature.
A Half Demon has all the special qualities of the base creature, plus darkvision up to 100 ft. They possess damage reduction 5 vs acid, cold, or fire damage (must choose two), and are immune to either electricity or poison damage (must choose one). Half Demons can also communicate telepathically with any creatures that speak Abyssal, but only in that language.
+8 Str, +6 Con, +8 Cha, +6 Dex, +4 Wis
Half Demons have +10 racial bonuses to Intimidate & Perform
As the base creature.
Half Demons are too chaotic to form into any huge groups (Mostly armies or mercenary guilds) Choosing to fight alone or in small groups.
Any, but alignment changes to chaotic evil when transformed.
By character class.