A Year in the Valley

This slug was a medium-sized one at around 3cm in length.  I identified it as a Grey Field Slug.  It was grey and brown.  The colour of the Grey Field Slug varies but is usually blotchy or mottled, and the head and antennae are dark.  Another identifier is that its slime has a milky appearance, which you can see on the blade of grass that it has just left.  It is found in most habitats and is thought of as a pest (as are all its cousins!)