You can have your own tamed dragon by using the commands, but for a short amount of time. This is a very cool glitch. You can ride and control the dragon but when you ask it to attack a creature it will not and just stay still. It stayed around for maybe 10 minutes then disappeared leaving no trace of it behind.
Get 19 rexes with 40k health and 600 melee with mastercraft saddles. They will be used as crowd control for the dimorphs and teras. You will need a male deer with 10k health and a journeyman+ saddle. Get the deer under he dragon when it lands so it gets stuck. Have shotguns with 180+ damage to them shoot the dragon. And also, make sure you have journeyman+ tiered flak to bring in too!! 2-3 sets of armor recommended
First of all you can’t knock it out just like all other bosses. Second, in order to kill it I would recommend mutated therizinos with ascendant saddles, about 17 of them. You can give the therizinos sweet veggie cakes for them to heal on their own. I would bring 2 daeondons and 1 yuty which are both better when someone is riding them.