"A" is for "Atuu"

Atuu

No. Enc.:  1d4 (2d10)
Alignment:  Chaotic
Movement:  90' (30')
             Fly:  45' (15')
Armor Class:  4
Hit Dice:  9
Attacks:  2 or 1 (2 claws, or 1 wing-slash, or 1 weapon)
Damage:  1d8 +1d6 / 1d8 +1d6, or 2d6 +1d6, or by weapon +1d6
Save:  L9
Morale:  9
Hoard Class:  XXII
XP:  5,900

Embracing and channeling the constant pain that wracks their bodies, the Atuu are a savage race of avians that live for slaughter and conquest.  Broad and powerful, they stand 6'-7' tall, but their impressive head crests can add another 2'-3'.  The Atuu dwell in forests (in pyramid-shaped "nest-dens") and overgrown ruins, and raid surrounding villages for slaves, supplies, and precious technology.

Their feathers are as hard and sharp as the finest metal blades.  Anyone struck with a successful wing-slash attack on a natural roll of 16-20 [not a modified 16-20 from their martial bonus] bleeds profusely, and suffers an additional +1d4 damage per round for 1d8 rounds.

Besting—and killing—an Atuu chieftan (who has an extra +2 Hit Dice) in hand-to-hand combat is such an impressive, life-changing feat that the victor gains both the Intellectual Affinity (Martial) Mental Mutation, and a permanent -3 Reaction Adjustment when dealing with other Atuu.

Mutations:  Body Adjustment, Chameleon Epidermis, Increased Sense (Taste), Intellectual Affinity (Martial), Pain Sensitivity [D], Spiny Growth (Large)