When it comes to songs, one thing that always attracts my curiosity is non-greeks singing greek songs. One of the most humorous such cases is Donald Swann, of the legendary 50's and 60's Flanders and Swann duo, singing To Kokoraki (Το Κοκοράκι - The Cockerel), a satyrical traditional greek song. Before joining Michael Flanders, composer and pianist Donald Swann (1923–1994) studied modern languages in Oxford, and during World War II served in Greece "whose music and culture became a life-long passion and influence". In that sense his admirable rendering of To Kokoraki is not surprising.
Still, I think it's no small feat, as even native greek speakers can easily trip over their tongues trying to imitate the required animal sounds and going through the repetitions of this funny song.
This 1959 recording is from their musical revue At the Drop of a Hat. Swann's handwritten notes on the song are interesting themselves, with all the words mimicking the animal voices carefully written out. Greek listeners will easily recognize the tune, as it is a children's favorite and has been recorded many times. In Ζήτω το ελληνικό τραγούδι Dionysis Savvopoulos made a version where each animal voice was performed by another artist.
Perhaps the most famous Flanders and Swann song is the The Hippopotamus ("Mud, mud, glorious mud"). You can check out a couple of versions here - with a russian interlude - and here.