You knew we couldn't get through a whole year without meeting this guy, right? The slug is about 6 inches long or so, and the ones I've seen around here (which is not that many) have all been this tan color rather than the bright yellow for which they were named. The breathing hole can be seen easily here, but the eye stalks are almost lost against the background. To see some beautiful pix of yellow banana slugs in California, check out this blog. And to learn lots more about this shy and inoffensive critter, try this page. The clover-like leaves are wood sorrel. Various species of this plant grow throughout much of the world, but the coastal regions of northern Califiornia, Oregon, Washington, and British Columbia have their own species, Oxalis oregana, called redwood sorrel or Oregon wood sorrel.
I took the photo August 27, 2003, along the Cathedral Tree Trail back when there was more canopy cover for the slug and other shade-loving species.