The Dipper is like a big black-and-white Wren on steroids that spends its life on, in and around fast-flowing streams. It is highly unusual in that in addition to brief dips beneath the surface, this perching bird can swim underwater tilting against the current. Also, it can use its powerful feet and claws to cling to underwater rocks to stop it getting washed away.
An old name was Water Ouzel, ouzel being an old name for the Blackbird. With its superificial resemblance to the Ring Ouzel at least in pattern, you can see where it got its name.
The Dipper is also called the White-throated Dipper, to distinguish it from other dippers around the world. Our local subspecies has a chestnut band beneath the white breast, while nominate continental birds have a blacker belly and are known as ‘Black-bellied Dipper’, which are rare visitors to the UK.