XCOM: Enemy Unknown Edit
Chryssalids are swift, four-legged alien with terrifying melee capabilities and a fairly strong poison. Strangely, their poison is ineffective against other aliens. When a Chryssalid kills civilians or soldiers, it will implant an embryo in them. This causes them to rise again as zombies, which will spawn a hatchling soon after (3 turns in-game). The one difference between an adult Chryssalid and a hatchling is that, being technically newborns, the hatchlings don't have the carapace that full-grown Chryssalids have.
Chryssalids only weapon is their claws, which, coupled with their speed, makes them effective against most targets. However, the Floaters and soldiers wearing the XCOM Project's Archangel Armour have proven to be the bane of this creature, able to fly out of reach and fire down on them.
XCOM 2 Edit
Chryssalids return in XCOM 2 as the aliens' primary terror unit, most often appearing during retaliation missions against Resistance hideouts. They have undergone considerable alteration since the invasion, appearing more physically imposing with the addition of razor-sharp spines across their bodies and a change in the colour of their chitinous skin.
As before, Chryssalids only attack at close-quarters. They rapidly pursue human prey and can even ambush their victims by burrowing underground and striking from below. Their attacks also inflict a terrible poison upon their victims that will transform the afflicted into a cocoon upon death. Unless it is destroyed before its gestation period ends, the cocoon will hatch into a new fully-grown Chryssalid.