Although his acting career was not limited to comedies, he was best known for his work in a comic trio in a series of films by Leonid Gaidai, with Yuri Nikulin as Fool (Balbes), and Georgy Vitsin as Coward (Trus). Their best-known films together were Operation Y and Other Shurik's Adventures and Prisoner of the Caucasus, or Shurik's New Adventures. Morgunov's character named Experienced (Byvaly) was always the "tight-lipped and aggressive leader of the group". Reportedly, "the three symbolized exactly what Soviet men were not supposed to be - drunk, unemployed and inclined toward mischief." In one of the legendary scenes in Caucasian Kidnapping Experienced gives lessons on how to dance the twist - by putting out cigarette butts with his feet.
