Spok dogs

Spok dogs are massive creatures that live in the barriers between universes, they are very violent and attack anything that comes towards them. Spok dogs don’t need to eat, but they still do. Spok dogs are usually around 5 miles long and 3 miles tall. Their skin is unbreakable, but nobody has even tried to break it yet. They are studied by universal scientists who try to figure out where they come from and what they are made of. These studies are challenged by low funds, and the low amount of trips that have been hosted to other universes.