Toxic Blood.  When the Xenomorph takes damage of any type but psychic, each creature within 5 feet of the Xenomorph takes 10 (3d6) acid damage.

Lethal Ambush. When the Xenomorph attacks and hits a surprised creature with a melee weapon attack, the final damage of the attack is tripled.

Sunlight Sensitivity. The Xenomorph has disadvantage on attack rolls and on Wisdom (perception) checks that rely on sight when the Xenomorph, the target of its attack, or whatever it is trying to perceive is in direct sunlight.

Feral Resilience. The Xenomorph has advantage on saving throws against being poisoned or frightened. Additionally the Xenomorph can take the hide action as a bonus action

Mutiattack. The Xenomorph makes three attacks. Two with its claws and one with its stinger.

Bite Attack. The Xenomorph makes one attack with its bite against a creature within range. The Xenomorph must have advantage on the attack roll in order to use this action.

Claws. Melee Weapon Attack: +9 to hit, reach 5 ft., 1 target. Hit: 13 (2d8 + 4) slashing damage. If a creature is hit by this attack, it must succeed on a DC 17 Strength saving throw or become grappled by the Xenomorph. While grappled in this way, the creature is also restrained and the Xenomorph can't make an attack with its claws until the creature is no longer grappled. 

Stinger. Melee Weapon Attack: +9 to hit, reach 10 ft., 1 target. Hit: 20 (3d10 + 4) piercing damage. 

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., 1 target. Hit: 28 (5d12 + 4) piercing damage.