Chryssalid

Lightning Reflexes. If the Chryssalid is subjected to an effect that allows it to make a Dexterity saving throw, the Chryssalid gets advantage to the saving roll, and if on a successful save the Chryssalid only takes half damage, the Chryssalid instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Leap. The Chryssalid's long jump is up to 40 feet and its high jump is up to 20 feet, with or without a running start.

Implant. If the Chryssalid kills a creature, it implants an embryo inside them, this causes the corpse to rise up as a zombie in the next turn, and will spawn a Chryssalid hatchling after two turns, resulting in the zombie being killed. However the Hatchling will not spawn if the zombie was killed before it hatched. Hatchlings possess behaviour and statistics identical to adult Chryssalids, but have a visually lighter colour of chitin armour which changes to the usual purple within a couple turns. A newborn Chryssalid can move and attack the turn it emerges.

Multiattack. The Chyssalid can make three Chryssalid Claw attacks.

Chryssalid Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one creature. Hit: 21 (3d10 + 5) slashing damage, and the target must succeed on a DC 15 Constitution saving throw or take 10 (3d6) poison damage and the target is poisoned.