The June word of the day today is "wild"! I have also tagged this for songtitle-75 challenge to go with the delightful "A Song for Slug" https://www.youtube.com/watch?v=9rpFhZcrV5U enjoy!
I believe this guy is an Arion ater (large black slug), one of the three species found in the UK. Whilst slugs are a serious pest to the gardener they are eaten by a range of wildlife including hedgehogs, foxes, badgers, many birds, slow worms, violet ground beetles and Devil’s coach horses.