Credit to scratchdewoof for this creature!

They travel through realms with portals that only certain species of creatures can travel through. Some of those creatures are creatures in the Walker family, but others are unknown. Only Voidwalkers can make the void portals. Voidwalkers can ‘help’ creatures pass through void portals by grabbing onto the creature and then traveling though the portal with them. Little is known about portal travel, although it has been said that when you travel through a portal you go into a secret network of portals, each leading to a different place. Their known habitat is either in their portals, or they hide in dark places. They are nocturnal, and it is very rare to see one during the daytime. If one is seen during the day, it is to warn of a disaster that is yet to occur