Who is this?

He's sitting up. He sits for 10-20 seconds unsupported. When did that happen? When did he grow up so much? Who is this little man?

Also, I just want to show you a picture of us trying to get him to sleep. He now fights sleep so much that we have to put this blankie (courtesy of aunt Jen) over his face just to get him to calm down enough to fall asleep. What a stinker!