Giant four-legged bird from the Abyss, resembling an ostrich with a short neck

Though not demons, achaierai are native to the Abyss. They are giant birds, somewhat like ostriches with short necks and four legs each. They attack as 9 hit dice monsters. Their bite attack (1d10 damage) is usable only against foes they can reach—typically those flying or over 8-ft tall. Against smaller creatures they have only two attacks with their talons. Creatures under 8-ft tall, however, are at an equal disadvantage against achaierai. They may hit the creature's body (AC 8) only with missile weapons, spears or polearms (such as pikes). If armed with a hand weapon, they must attack the achaierai's legs (AC -1).