I made my entity carry 2 passengers but how do I make the second passenger(usually pets) but what happens is that the non player passenger is able to control the dragon. Also I like the feature that the second player is the one unable to control the dragon. https://pastebin.com/UDGhVh27

Is this part of your code supposed to prevent the second player from controlling it?

800.

@Override
    public boolean canPassengerSteer() {
        // must always return false or the vanilla movement code interferes
        // with DragonMoveHelper
        return false;
}