Spanish or Lusitanian Slug

Hmmm, time for another mollusc. Not as cute as the Door Snail but certainly commoner, in the south at least. This is an invasive species, originally referred to as the Lusitanian slug but now usually known as the Spanish Slug: Arion vulgaris. It lays more eggs than our native slugs and they are more resistant to drought. It also has a less discerning diet.
This one is chasing a leucistic cousin.