He debuted in the 1966 novel Gena the Crocodile and His Friends (ru) by Eduard Uspensky.

His two best-known songs are "Pust' begut neuklyuzhe..." and "Goluboy vagon" ("The Blue Train Car").

One rainy day, which happens to be his birthday, Gena sings the song: "Let the pedestrians run clumsily over puddles..." ("Пусть бегут неуклюже пешеходы по лужам..."), which contains the famous line: "Such a pity that one's birthday happens only once a year".

The Mikoyan MiG-27 aircraft was given the nickname Крокодил Гена due to the distinctive shape of its nosecone.

Arty Alligator (played by Christopher Bradley but unvoiced) from the 2021 American action comedy horror film Willy's Wonderland[2] was inspired by Gena the Crocodile from the 1969 Soviet stop motion animated Cheburashka cartoon Gena the Crocodile.