Looks like a slowworm, but it's a big 'un!
Also, it's never lost its tail. As when they do they grow back much stumpier/shorter.
Lovely thing to see.
Monster slow worm! Cool!
I think it's an Oak, but the bark on the branch is a little unusual looking.
Black mamba
Was it on a plain?
They are misnamed though aren't they? I disturb ed one in a garden waste pile , it was ideal in there warm and toasty! I just about managed to grab it and put it back in it's warm hidey hole , boy can they move!
Looks like a female slow worm, the flanks are darker than the top. You can record the sighting here:
https://www.recordpool.org.uk/index.php?option=com_content&view=article&id=13&Itemid=6
Some male slow worms have blue patches, the same colour as sloes (the ones for sloe gin) and apparantly thats how they got their name (sloe worm) but the spelling changed with time.