Harmonium (fictional creature)

According to The Sirens of Titan by Kurt Vonnegut, harmoniums are the only form of life on the planet Mercury. Harmoniums are paper-thin cave-dwellers that feed on nearly undectable vibrations in the planet, described as "Mercury's song." Harmoniums are kite-sized and kite-shaped, and reproduce asexually by flaking off in a manner not unlike dandruff. They have only the sense of touch, and also rudimentary telepathic powers capable of only two messages: "here I am, here I am, here I am," and "so glad you are, so glad you are, so glad you are."

Harmoniums are a semi-transparent blue, making the yellow walls of Mercury to appear aquamarine beneath them. When they die, they shrivel up like dried fruit. They can die from feeding off too much vibrationfictional-stub

The Harmonium is also a fictional Faction Guild in the Dungeons & Dragons campaign setting "PlaneScape".