Blood Frenzy. The Yaomo has advantage on ranged attack rolls against any creature that doesn't have all its hit points.

Relentless (Recharges after a Short or Long Rest). If the Yaomo takes 7 damage or less that would reduce it to 0 hit points, it is reduced to 1 hp instead.

Flyby. The Yaomo Emissary doesn't provoke an opportunity attack when it flies out of an enemies reach.

Limited spines. The  Yaomo Emissary has 15 tail spines. Used spines regrow by the time the Yaomo Emissary finishes a long rest

Multiattack. The Yaomo Emissary makes 3 quill attacks.

Bite. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 2 (1d6 - 1) piercing damage. 

Tail quills. Ranged Weapon Attack: +5 to hit, range 20/80 ft., one target. Hit: 6 (1d6 + 3) piercing damage.

Poison breath (Recharge 5-6). The Yaomo exhales a 15ft sphere of gas centred on itself. Each creature in the area must succeed on a DC 11 constitution saving throw, taking 9 (2d6+2) poison damage on a failed save as well as becoming blinded for 1 minute if they are not a Yaomo, or half as much on a successful save and they do not become blinded. A blinded creature may repeat the saving throw at the start of each of its turns, ending the effect on it on a success.