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.

Dr. John B. Burch, Ph.D. (photographer, copyright holder), Mollusk Division, Museum of Zoology, University of Michigan