Location: In the Queen's Hive
Threat Assessment: 4. When the eggs can kill you, you know you are dealing with some badasses. Capable of staying viable for centuries, they will hatch when lifeforms come near. Then like a demented jack in the box out pops the face hugger.
Limitations: Don't move. Can be set on fire.
Person Note: Eggs so scary it was on the poster of the first Alien movie. That's a bad ass egg.