Ariolimax columbianus, from the Olympic Peninsula, Washington. Ariolimax columbianusis a native of the West Coast, from Alaska to the western slopes of the Sierra Nevada. This is a large slug, often approaching the size of a banana, and often the light yellow color of a ripe banana, hence its common name, "the "banana slug." The banana slug is the mascot of the University of California at Santa Cruz.
John B. Burch (photographer; copyright holder), Mollusk Division, Museum of Zoology, University of Michigan-Ann Arbor