AP18 is the biggest and oldest bull in his pod.
Though he will not sire any calves within his own pod, his sheer size and old age means he (barring any reproductive problems) has likely sired many calves in other pods. For reasons we still don’t totally understand, female killer whales prefer to mate with with old, large bulls. There is likely some aspect of mate choice but recent evidence of infanticide in other killer whale populations suggests that females may not have much say in some instances.
Due to the fact they spend nearly their entire lives underwater, we know virtually nothing about the reproductive behaviors and courtship of killer whales!