sizes

hey I was just wondering as I just received my first golden casket drop. and I need to use a Casket Key in order to open it without receiving -%66. could anyone make a list of what monsters drop caskets and casket keys? or if so guide me to a forum that already has. I can't seem to find one. and people say only way to buy a casket key and some say basilisk knights drop keys.. idk just help me out please.