UPDATE: Booge has discovered that this is a conch. Well done, booge.
Photo source: Knuttz.net

I can only assume that once Starbucks catches wind of this they'll begin an intensive study of the banana slug to see exactly what causes such cravings, and then have that chemical added to our drinking water. If in a few months you find yourself upping your coffee consumption and secreting a protective slime coat, then you'll know I'm right.
Thanks, Rick. Not everyone has the presence of mind to take a picture of the slugs drinking their coffee.