Korovyev (spelled Koroviev in the Penguin Classics edition) is one of Woland's entourage in Mikhail Bulgakov's novel, The Master and Margarita.
"[5] He is close with the mischievous Behemoth, the oversized-cat-like demon in Woland's party who can alter his appearance at will to seem like a human man.
In Chapter 28, "The Last Adventures of Koroviev and Behemoth," the gruesome twosome wreaks havoc around town,[6] sowing confusion at Smolensky marketplace and starting a fire at Griboedov's, a restaurant and meeting house for Russia's literary elite.
He enjoys telling blatant lies, such as pretending to Ivan when the latter returns from the site where Berlioz died that Woland, to whom Ivan had just recently been speaking, all of a sudden cannot speak Russian;[7] and declaring confidently to the door attendant at Griboedov's that both he and Behemoth the Cat Demon are in fact writers.
")[9] and threatening a shopkeeper who warns him that "We only accept currency" that he will file a complaint with the manager and "tell him such tales about you that you may have to surrender your post between the shining mirrored doors.