What the $%^& is this?!

[Staycalmandscream]

It just crawled across my lounge floor. Fast mover. About 12mm long.

Help!

Stag beetle (female). They are harmless and, I think, endangered. Slide onto a piece of card and pop it outside.

Bog standard beetle?

Just a beetle. Harmless and good for the world so please put outside!

Oh no sorry, looked again and it looks more
like a black clock beetle.

Christ put a warning in your heading, that's freaking gross...

It’s a Carabid beetle/ground beetle, harmless beneficial insects which eat pest species, bung it outside and it’ll be on it’s way 😀

Some beetles are indicative of other issues so I wasn't sure if this was a worrying appearance.
Apart from the general worry you get seeing something like this