Narslog are huge black slug-like creatures. They live in caves and tunnels and because of this are completely blind. They rely on their hearing and sense of smell to navigate and detect prey. Their bodies are coated with an excreted black slime and they have tentacles with retractable neurotoxin-injecting spines.
Narslog are massive, growing up to several times the size of a minifigure and two to three the size of a giant spider. In the center of the many spiny tentacles and feelers on its head is a circular mouth lined with curved white teeth.
Narslog eggs are black and bulbous, and pulse with the warmth of the creature inside.