Lucky is hormonal and needs to have you become dominant over him. And mean it . Every time he goes after someone get him down on his belly hold his head down so he can't bite hold him there for as long as it takes him to stop fighting, once he stops let him up facing away from you. If he comes again do it again. He needs to see you as the dominant one. Your treating him just like another drake would do to him. I went through this with my drake almost 7 yrs ago he is my boy now. It isn't an instant lesson it takes consistency and reminders too . If you have young kids teach them to use the broom to keep him away as soon as he starts for them place the broom between him and them even sweep him away if he won't give up.