That's either the biggest dog I've ever seen, or the smallest, non-midget, proportional human I've ever seen.
"But Ed", you incorrectly point out, "it's camera perspective. The dog is closer, therefor he appears larger."
Wrong you are, dumb reader. That's just one huge dog! He's got to weigh like 200lbs, maybe more. What is that, a Bullmastiff?
I found this picture over at CaptionThis.