A funny imitation of a poem

One word substitute is Parody.

Counterfeit: made in exact imitation of something valuable with the intention to deceive or defraud.
Sonnet: a poem of fourteen lines using any of a number of formal rhyme schemes, in English typically having ten syllables per line.
Caricature: a picture, description, or imitation of a person in which certain striking characteristics are exaggerated in order to create a comic or grotesque effect.
Parody: an imitation of the style of a particular writer, artist, or genre with deliberate exaggeration for comic effect.