Steps to tame the "bob killer"( raptor) are:-

Take bolas

Take a knockout weapon

Bola the raptor

Knock out the raptor

Feed it meat

Raptor is tamed!

You can also aggro the raptor on any herbivore( weak ones like parasaur, turtle or dodo) and wait for the raptor to kill it. Then do the above given steps. The raptor will be tamed much more easily as its health is decreased by fighting the herbivore.