Built a pen to lure and trap a 150 ferox using bloodstalker, worked fine. At the 50% mark ferox duplicated into two extra ferox for a total 50% done on each one ended up with 3 max level triplets. But level did not increase after taming until i cryopod the feroxes
First of all, keep him out of the light, he hates bright light, especially sunlight, it'll kill him. Second, don't give him any water, not even to drink. But the most important rule, the rule you can never forget, no matter how much he cries, no matter how much he begs, never feed him after midnight.