Clan Verminus
Clan Verminus is a new Great Clan unique to Age of Sigmar. As the Great Clans in AoS are instead a type of Clan (So a plague-infested monk Clan will be a Pestilens clan among many), the "Clans Verminus" is essentially the old Warlord Clans. They're all Skavenslaves, Clanrats, Stormvermin and Warlords; none of the fancy shit. Then again, if you can't win by throwing thousands upon thousands of warm, ratty bodies at the enemy, how can you say you're playing Skaven?
Lore wise, they’re described as the most numerous, most aggressive, most territorial, and most fractious of the Great Clans. Its many warbands are always fighting amongst each other constantly. They worship the Great Horned Rat as the multi tailed King of Lashes, a conquering ruler who rewards only the ones who successfully slaughter his enemies.
They originated from two Warlord Clans from the World-That-Was; Clan Klaw and Clan Skarrik, the latter of the two likely being some descendant of Clan Mors due to their red armor. From these two, a multitude of other ravenous clans were unleashed upon the Mortal Realms. Interestingly, some of these clans bare stark similarities to older Warlord Clans, implying some old traditions still live on.