The Cosmic Battle Crabs are considered to be a failed experiment by Vampira Infernalis to create a new type of minion for war.
Due to poor temperament, these creations were left to their own devices on the planet where they were engineered. Seven species are currently known to exist. All continue to grow throughout their lives, reaching immense sizes.
In recent times, Horsemeat the Lobster Rider has rallied them to fight against Vampira.