These are limbless lizards and a beautiful golden copper colour.
If you find them in your garden they love to make a safe place to hide under stones or sheets of corrugated iron.
I had an offcut from a plastic drainage pipe which I upended and place on a concrete slab and filled it with dried leaves before the winter. I covered the opening with two slates.
Last week I lifted the slates and the slow-worms are back and nesting.