Stray showed up at the house

This pup showed up at the house, we think someone dropped it off (it’s common around here).

Took it to the vet and it’s not chipped. We have it posted locally but no one seems to know where it came from.

We have no idea what breed it is, just know it’s gonna be a large dog by the looks of its paws.

Wife and kids want to keep it, so I’d like to know what breed it possibly is. Seems like a super mutt.