Fairly easy to tame just get yourself a good level rockdrake and bring along some arrow, a crossbow, a magnifying glass, and a light pet. Once you have gotten the materials just go down into the radiation zone and find your self a queen reaper, from there use your rockdrake to get its health below 2000 constantly check when she starts to get bloody. Once you’ve gotten her below 2000 health (she will glow red with light pet off when below 2000 health) turn off your light pet and start to shoot her with your crossbow (this is so she agros one you not the rockdrake) and she will eventually dismount you and impregnate you. Depending on your hatching speed you can go out and kill things to gain extra levels on your reaper king you can get up to an extra 75 levels. Side notes: when impregnated don’t let yourself get radiation sickness it will kill the reaper. Also you can cryo it when it’s born to lose its agro before it’s a juvenile.