10: The Murder Slug – Mördarsnigeln (Arion vulgaris)
Just why this sticky critter is named the “murder slug” is a mystery to me. The worst thing they do is secrete a clear, harmless mucous when disturbed, which – at worst – can take a while to wash off. Slug victims have been known to describe the attack as ‘mildly irritating’ - so it's just their name alone which allows them a place on this list... but only just!
Photo: Håkan Svensson, Xauxa/WikiCommons (file)