bullmastiff
An Awesome dog breed originating from england; mix of mastiff and bull dog.   Originally used by estate game keepers to engage poachers and hold them to the ground without mauling them until the game keeper arrived.  Extremely terretorial and protective of its owners and property.  Good family dogs for people who have time.   
The bullmastiff quickly tore the trespasser down in a powerful leap.

The bullmastiffs didn't miss a beat after eating a four pound bag of quick dry cement.

After being kept in the kitchen all day, the bullmastiff decided to chew his way through the wall into the hallway.