My sister's Olde English Mastiff, Frasier, is pretty ginormous, too. I'm 6' tall, he stands around waist-high, w/his head pretty much level w/my chest...He can easily put his island-sized paws on my shoulders, & his head is about the size of a bushel-basket. Dunno what he weighs, but I'm guessing easily in excess of 200 lbs...He's a big teddy-bear, too, he will take a doggie-treat easily out of yr mouth, altho I must admit to a bit of trepidation the 1st time I tried THAT trick. Yet he IS somewhat dangerous, not out of temperament, but just because of his huge size..He can easily hurt you just by "playing" w/you, an otherwise friendly swipe from a huge paw, could half-rip yr face off. But still, when you see him, all you wanna do is get in his fenced-in area w/him, & "wool" him...