We had neighbors who had a female mastiff, not even fully grown, she weighed 165 pounds.
I saw one of the owners in the supermarket and she was pushing two carts, one for them, and one for the dog.
The dog was gentle, but I got very nervous when she wanted to play with our four year old.
His entire arm disappeared into her mouth for a second, but he was just fine, only got slimed.
I was walking through an area of local woods that’s frequented by homeless. There was a family of five...three young children....walking through, and a skinny 100-or-so pound dog that barked and charged at me. The husband apologized for scaring me. I told him that mastiffs generally didn’t worry me, as they aren’t really known to be biters. The little four-year old girl looked at me and said “He’s not a mastiff. He’s half Cane Corso and half Presa Canario.” OK, then.