Water Scorpion (nepa cinerea)

This is a pond predator which lurks in ponds waiting for any small creatures to grab with its front legs (which look more like giant pincers). It can give you a painful nip if you handle it, but it is not poisonous. Still, we wouldn't recommend picking one up.

It looks like it has a large sting coming out of its tail end, but actually this is a snorkel which enables it to breathe whilst staying just under the surface of the water.