I have a frizzle batam cochin (5 weeks) that crowed for the first time yesterday (very funny) but today he decide to take on my Golden Lakenvelder Roo (4 weeks). The GL is bigger but that didn't stop anything. When I went to break it up the frizzle had him by the neck so well that I picked up the frizzle and the GL came with him. He had been dragging him around by the neck. There was no blood but it is all out war between the two. I broke up at least 4 more fights and they keep a constant eye on each other. I know at this age they play fight a lot to establish pecking order - but is that kind of viciousness normal?