Tragical Accordion Snail

"Accordion Snail" is the common name given to a range of gastropod mollusk species that develop shells resembling musical instruments such as the accordion, squeeze-box, and concertina.

Evolution and Distribution
Accordion Snails are a product of convergent evolution, meaning that their instrument-like shells appear to represent a common adaptation to similar environmental pressures in different places. Consequently, mollusks which are referred to in this way are rarely linked by close genetic lineage. Similar organisms which employ this adaptive strategy are the Kazoo Wasp and the Giant Tartan Bagpipe Jumping Spider that Nobody Likes.

Accordion Snails proliferate in and around the outskirts of urban regions where the human population has taken a cultural dislike to music associated with particular instruments. Unmolested by homeowners and farmers wary of evoking an unwanted timbral signature, these animals are able to flourish through a relative lack of competition by other organisms which fall pray to aggressive removal. The Tragical Accordion Snail earns its descriptive epithet when this strategy fails (often as a result of a local fusion scene or folk music revival event self-consciously employing unpopular instruments), leading its brittle shell to be enthusiastically crushed.

The Accordion Snail has been notably extinct in France for some time, unsurprisingly, but is growing as an import following its cultural reintroduction by Dr. Gustavo Bunkleschmidt.

Music
The accordion snail is notably bad at playing the accordion