What is the Bizarre creature in North Carolina Sewer?

Poem about a creature dying

• Asking for a friend: help identify this poem please! Here's what she says about it: Six years ago I was at a summer program in North Carolina and attended a poetry reading (not a reading by the author, just a reading of published poems) where someone read the first poem I ever really appreciated. All I remember about the poem is that it was of medium length (if it were printed I think it would take up one to 1.5 pages single-spaced; it took about five to eight minutes to read); the writing was full of fairly dark imagery; it depicted a strange creature that seemed to have elements of intelligence and personality, though more like a graceful wild animal than human. I remember particularly vivid imagery depicting how the creature moved--unpredictable but graceful shambling or stalking. I don't exactly remember the setting except that there wasn't much of one. It may have been that the entire poem took place in a small bare-walled room or something of that nature--the setting was bare and the creature didn't leave. The progression of the poem depicted the creature suffering and dying from being trapped, but I remember thinking that it wasn't trapped in as much a physical sense as much as this creature was the wild part of a person's nature that they were suppressing and the creature was suffering and dying, almost wilting, as a result. The behavior of the creature went from graceful and aggressive to defensive and eventually almost catatonic. I don't remember how the creature was described to look but my vague recollection is that it was a smooth mottled purple or other dark colors, and thin, almost skeletal, but highly muscled. To the best of my recollection the poem was free verse but in a non-abrupt style, sort of like very descriptive prose. If it was in any of the typical poetical literary forms it was very subtle. Thanks for any help!

• Answer:

  Was it Elizabeth Bishop's http://www.poetryfoundation.org/poem/176997?