Megarachnids had eight legs, with four legs used for locomotion and the other four ending in sword-like claws. Their entire bodies were covered in an organically-produced metallic substance that made their claws so hard that they were able to easily cut through the Ceramite of a Space Marine's Power Armour, and their hides proved resistant even to Bolter rounds. When this metal exoskeleton was breached, the Megarachnids bled grey blood and had pink flesh contained within their armoured hides.