I’ve been mulling over the same thing. I am wondering if roosters with the hawk-like eyes and look are more aggressive than those with more rounded, and dark brown eyes. I don’t have a lot of rooster experience, but I have found that the hens with big, round, dark eyes are friendlier than those with the hawk-like look.
For now I’d just make sure the 3 year old is well supervised around him.
The shape and color of the eyes is breed specific.
They're so pretty! Thank you for the suggestion! I have heard that Lavender Orpington roos and Swedish Flower Hen roos are typically docile, but I know every chicken is different. My guy was great until he hit 7 months and no matter what I did he still was incredibly aggressive towards everyone. When he attacks my husband he holds him down on the ground for a few seconds and then picks him up and holds him for a few minutes. I take a stick with me when I do chicken chores and try to show him who's boss, but that seems to make him more mad. I've also tried to distract him with treats. Nothing works.
IMO, docile birds are more susceptible to predators because they just lose their fear of things. On 2 separate occasions, I witnessed a fox grab an orpington hen in the middle of the afternoon. The hens weren't even aware anything was afoot till they were in the jaws. That would never happen to an alert, 'flighty' breed. They see everything and fear everything. A fox may still kill a leghorn or Minorca but the bird would know it was there.
You need to re-home him or sell him ASAP. It just takes a second for tragic things to happen. This child is NOT SAFE.
X2
One that has attacked is too unpredictable to keep around.
Hi, I HAD the same problem and he only got worse when people came over. Last week he attacked me and broke my arm. He was a large Barred Rock, which are usually a lot nicer, I don't know why he got like this but I had to put a stop to it. He actually injured several Family members but I wouldn't take a chance on him nailing 1 of my Grandkids. FYI, my Hens are much happier, too. I tried several things, clipped his wings, trimmed his Claws, (back ones), even tied Him up. (that was heart breaking and I'd never do it again) but he just got more aggressive, the more I tried to intervene. I hope someone out there has a better solution then what I had to do.
"broke my arm"

Interesting. Most of those that attacked me were Plymouth Rocks too. If I remember correctly, White Rocks and Partridge Rocks.
Ugh it's so hard! I love him because I raised him and he is my first boy, but at the same time I hate him and he terrifies me and everyone else. I just can't seem to correct his behavior. I'm so sorry you were injured. That sounds terrible!
No matter your history with him, there are just too many non human aggressive roosters in the world to saddle yourself with one like you have. As I said, there are over 6 billion excess roosters culled every year, yours will just be another one.
The sooner you end it, the more tender the meat will be.
I know how you feel, I raised mine from a Baby too, you can not correct their behavior , think they're not so bright, lol but not as stupid as people think though. I've had experiences with Roosters like this my whole life. Just got back into it over the last year after 10 years, guess I never learned my lesson, just thought this guy would be ok. I have another guy, he's fine. He's a smaller Icelandic, very happy now. Wish I had better news, perhaps someone has an idea. Good luck.
X2 I really think they are pretty intelligent for a creature with a tiny brain. At least in chicken things. They don't have to learn to drive a car, use a computer or do complex math but for all things that concern them, they're quite smart.
What people need to remember is that the rooster's job is to protect his flock. That means finding food and standing guard while the hens eat, putting themselves in the way of predators, breeding the hens and keeping peace in the flock. So the hens are his hens, not yours. If one handles their hens during the day, the rooster will see that person as a threat to his hens. If people must handle the hens, do so after dusk after they've all gone to roost. I think this philosophy is one of the main reasons I've had over a hundred non human aggressive roosters.
If one must play with their lap pet hens, don't keep roosters.