Rokken are the tanks, they are units that are just hard to kill. They are the very few of the USA who are granted the Frostmyrth armour. Instead of a custom marker they have to bear the USA sigma, and it is always purple. The Rokken are lobster type creatures, apart from they look human, they just have a carapace and that is also thick, so a thick carapace and a suit of Frostmyrth armour make these a formidable foe to fight. They are normally red or orange. Their leader is called Issen.
They come from a planet called Justratus, which is a planet where water covers 90% of the planet. It is enriched with many different sea life, which is where their food comes from. Herbivores also survive by the plankton that also lives in the water. The Rokken are the Sentinent species on their home planet and live on the 10% of land.