"Half-Oni" is an inherited template that can be added to a living, corporeal creature with an Int score of 4 or more. A half-oni uses all the base creature's statistics and special abilities except as noted here.

CR +1

Type: The creature's type changes to outsider (native, oni) and retains any other racial subtypes it may have. Do not recalculate HD, BAB, or saves.

Special Qualities: Gains darkvision 60 ft, regeneration 2 (fire or acid), darkness or invisibility as a spell like ability useable 3/day with a caster level equal to its class level.

Abilities: A half-oni gains +2 to Strength, Dexterity or Constitution and -2 to Charisma.

Skills: A half-oni with racial HD has skill points per racial HD equal to 6 + Int mod. Racial class skills are unchanged, and class level skill ranks are unaffected.

As the Oni are capable of taking on the form of a humanoid, crossbreeding can occur. Regardless of which type of Oni spawned the offspring, the resulting creature is known as a half-oni, or simply "half-breed" in Oni society. The most common half-oni are part Tengu Oni or part Serpent Oni. The first because of how low in the caste system the Tengu Oni are. The second usually due to religious ceremonies. A half-oni, at a cursory glance, does not look much different than the non-oni parent.  A closer inspection will reveal unnatural features, such as fangs or skin discoloration or oddly colored eyes.