The Mikoyan-Gurevich MiG-21 is a supersonic jet fighter and interceptor aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. Its nicknames include: "Balalaika", because its planform resembles the stringed musical instrument of the same name; "Ołówek", Polish for "pencil", due to the shape of its fuselage, and "Én Bạc", meaning "silver swallow", in Vietnamese.