Ah, yes, puppy days! They can be insane little devils when they want to!
Thankfully, I can tell you that to a point, they do grow out of it...just a bit!
With some firm teaching and patience I am sure your little guy will be back in angel shape in no time!
Treasure the time you have with him while he is a puppy, they grow so fast! I remember when my baby girl was 12 weeks old like it was yesterday and now she is already 6 months old!