Therapsida: Megawhaitsia patrichae

Megawhaitsia is a genus of huge therocephalian from another one of the many faunal assemblages of Permian Russia, amongst the largest of its family, Megawhaitsia rivalled inostrancevia for the largest predator on its habitat, though the scarce and few remains make it difficult to know just how fearsome it was and how it actually looked like, considering we only have part of a skull. 

Therocephalians were amongst the most terrifying predators from the late permian and are known to have taken on a massive variety of shapes and sizes, from small rat like forms to formidable predators such as Lycosuchus and Pristerognathus. They were very close kin to cynodonts and mammals and could've likely already have a coat of fur. Some members of this clade were also apparently venomous, making them unique amongst synapsid predators of the time.