The skin of this particular cactus is much too thick, although I've seen snails do damage to new pads on prickly pears (opuntias).
By the way, the snail is no more.
The Wednesday Vignette meme is hosted by Anna Kullgren over at Flutter and Hum. You can read her current Wednesday Vignette post here. Be sure to check out the links to other blogs that are also participating.