The abyssal portal is a portal that leads deep into the Abyss, and was created by Xeric. While admiring the other world, Vespula flew through the portal and attacked Xeric's crew, who fled the scene. Vespula now controls the area and tends to her offspring while protecting the portal.
Players can destroy the portal if they encounter Vespula, but only when Vespula lands on the ground, which will occur when she reaches 23% of her hitpoints. If the portal is destroyed, Vespula and her offspring will die as well, ending the encounter. If any of her lux grubs grow into vespine soldiers, Vespula and the abyssal portal will both regain hitpoints.