Space Wolves, once the VI legion of the twenty original Space Marine legions. Their primarch, Leman Russ, was one of the mightest warriors of the Imperium, known for a fierce and wild personality. The Space Wolves were instrumental in carrying out the destruction of the XV legion, the Thousand Sons, and decimating them on their homeworld on Prospero. The Space Wolves suffer a mutation that lead them to develop wolf like features, with their Scout Company's failed initiates and battle-brothers who lose discipline in the midst of battle mutating into monstrous creatures known as Wulfen. Rejecting the Codex Astartes, they are composed of 13th Companies, with the long-lost 13th composed of the forgotten battle brothers who have turned into Wulfen after millennia in the Warp-space wormhole known as the Eye of Terror. Their chapter master, or Great Wolf, is Logan Grimnar.