You're a lizard, Harry

Ever since I've started taking photography more seriously, I've noticed how my observation skills have improved. I don't remember ever encountering a lizard outdoors before. Recently, I met my first one on a walk through a nearby park. Fortunately, I had my camera with a telephoto lens at hand. This little fella gave me half a minute to take lots of pictures, before disappearing in the burrow.

I'm not entirely sure, but my research suggests it's a viviparous lizard (Waldeidechse in German).