"And Volkov and Vulchanov had better get back on those brooms. . . yes. . . there they go. . ."
-- Ludo Bagman's commentary during the 1994 Quidditch World Cup (GF8)
Along with fellow Bulgarian Beater Vulchanov, he was on the Bulgarian side that lost the 1994 final against Ireland. His other teammates were Viktor Krum as Seeker, Dimitrov, Ivanova and Levski (Chasers), and Zograf the Keeper (GF8). The events of the tournament were overshadowed by the chaos following the appearance of the Dark Mark (GF9, Pm).
By the time of the Quidditch World Cup tournament in 2014 (won by a team from Bulgaria captained by Krum), he and Vulchanov are considered “legendary” and are thought to be the best pair of Beaters in living memory (Pm).
Aggressive and legendary beating skills
Volkov derives from the Russian word volk meaning "wolf" (Behind the Name).
A videogame with Famous Wizards cards gives him a first name of "Ivan".
Lexicon list of Beaters
From the Web
Writing by J.K. Rowling on Pottermore:
Pottermore enhanced reading experience: Quidditch World Cup
Screenshots of the original Daily Prophet coverage of the 2014 Quidditch World Cup on Pottermore: Imgur archive
Harry Potter Wiki: Ivan Volkov