In Master and Margarita, Koroviev (or Korovyev) is part of Woland's entourage. In various scenes, he is called by his nickname - Fagot:
The magician sat down. ' Tell me, my dear Fagot,' Woland enquired of the check-clad buffoon, who apparently had another name besides ' Koroviev,' 'do you find the people of Moscow much changed? '
As far as I know, this is a translation from Russian фагот which means "bassoon", a musical instrument also known as fagotto, faggot, fagott or fagot, which you can see below:
Earlier, Koroview described himself as an "ex-church choirmaster", he is also apparently very tall and skinny, just like the instrument - is there anything else to his name?