If you have a two year old, even the best protector in the world is not worth his face or possible eyes. They are just chickens. Aggressive roosters tend to get more aggressive. They tend to attack children first, then women and then men.
I am wondering if this is your first time with chickens? Because I have found that roosters just raised together with flock mates, grow faster, get bigger, and there is nothing bigger to thump some manners into them. In my experience, they tend to become very aggressive and out of control.
I would think nearly all posters on here, come with advice from their point of view. But upon consideration there is a lot of difference between a newly established flock of five, kept in a backyard, sharing a space with children and a flock of 20 that has been established for 20 years, with birds coming and going into it.
Rooster chicks being raised in a multi-generational flock, are not the biggest bird in the flock. Size is important in chicken society. They learn they have to prove themselves. And their interactions with humans in not, being held all the time.
Cull this one. This is how you do it. Wear a coat or a long sleeve sweat shirt. Take a towel with your hands placed at the long ends, flip the towel over the bird and grab the bird firmly. Do not let go, even if you don't get a perfect grab, hang on and gather him in close.
Holding on to his legs, he will flap a bit, and then calm down. Put a cord around his legs, and slit his throat.
If you think you can't do this, think about protecting your son. Can you protect him? You don't have to eat him. A lot of people can't.
Do not feel guilty about this, think of your child. Would you keep a dog that bites around a child? No, I am sure not. Look at the size of the brain in the rooster, regardless what anyone says, there is not a lot of brain there to train.
Roosters are a crapshoot, some are worth keeping, and some are not.
Mrs K