What is the name of Lewis Carroll's nonsense poem about a crew hunting a mythical creature?

Lewis Carroll’s nonsense poem about a crew hunting a mythical creature is The Hunting of the Snark.

Published in 1876 and subtitled An Agony in Eight Fits, the poem follows a crew of ten who sail in search of a Snark. Their leader, the Bellman, navigates with an absurd map of the ocean, while the crew includes characters such as a Baker, Banker, Barrister, Butcher and Beaver. Carroll uses comic logic, invented words and escalating danger to create a work that is playful but also strangely unsettling.

The Snark may be an ordinary imaginary creature—or a dangerous Boojum. Carroll never gave “Snark” a definitive meaning. Near the end, the Baker finds the creature and then vanishes “softly and suddenly,” confirming the warning that a Snark who is a Boojum causes its hunter to disappear.

The poem is sometimes confused with “Jabberwocky,” another Carroll nonsense poem, or with “The Walrus and the Carpenter,” a poem from Through the Looking-Glass. The Hunting of the Snark is distinct, though it borrows several invented words and creatures from the Jabberwocky setting.