We see this slug in the San Francisco Bay Area when we hike in some of the parks. They seem to prefer the moist redwood forests above the Pacific. This photograph was taken in Purisima Creek Redwoods Preserve.
Interestingly, banana slugs are "simultaneous hermaphrodites". They carry sperm and eggs, and exchange sperm with a mate. I believe they can also self-fertilize.
It is the mascot of UC Santa Cruz.
Ed
