He is so hard to tame and needs so many things here is the tips

1:need a fast Flyer to make him follow you

2:make a trap of like 7metal gateways behemoth

3:get him into your trap and make sure he won't get out

4: get your weapon and start shooting him with the crossbow or longneck(i recommend ascendant longneck)

5:after you down him get raw prime meat(the best is kibble and mutton)

And finally make sure you don't make him take sp high DAMAGE because he will kill you