Conchobhar asked his nephew, Sedanta, to go with him but the boy refused. He and his friends were still playing. So Conchobhar told the boy to follow after them once their games were done, and took his leave.

The king and his guests made their way to Culan's home, where they were welcomed with ceremonies according to their rank. Mats were put down, fresh reeds spread out, and the hearth fires kindled. Drinks were served and the company began to celebrate.

'Have you any others following?' the smith asked his king.

Conchobhar, forgetting his nephew, said he had not. So Culan unleashed his bloodhound to patrol his grounds.

Culan's bloodhound was the fiercest hound in the area. When his chain was loosed, no traveler could get past him alive. He was strong enough to do the work of a hundred of his species. He was swift, strong, rude, pugnacious, surly, wild and savage.

Sedanta followed his uncle's entourage, taking along some of the things he and his friends had been playing with that day. When he reached the home of Culan, he threw all of his toys over the wall except one ball.

The bloodhound saw the boy and began baying at him. His baying was so loud that it was heard in all the tribal lands. His intention was not to frighten the boy, but to swallow him whole in one gulp.

Sedanta had no other means of defence besides his ball. So he threw that down the hound's gaping jaws. The ball traveled through the dog, stripping his innards out the back end of him. Then Sedanta grabbed the dog by two paws and slammed him against a tall stone in the yard until the animal broke apart and scattered all around the yard.

'Alas, men of Ulster, it is a sad day that we came here to feast," Conchobhar said on hearing the hound's cries and understanding that his nephew had come following them.

'Why is that?' the assembly asked.

'Because my nephew, my sister's son, Sedanta, has been killed by the hound.'

All the guests jumped up and ran out of the house. But Fearghus got there first and picked up the boy and rode him on his shoulders to his uncle.

Culan came out of the house and saw his beloved dog's remains scattered all around the yard and his heart beat as though it would burst for sorrow. He made his way to the crowd.

'You are welcomed, for your mother and father, but not for yourself,' Culan told the boy.

'Why are you angry at the boy?' Conchobhar asked the smith.

'You did wrong to come to me, to eat my food and drink my drink. For now my most prized possession is gone, my livlihood is taken from me. The bloodhound which is scattered around the yard guarded my lands and flocks and herds for me.'

'Father Culan, do not be angry. I will give a just judgement on this,' Sedanta told the smith.

'What judgement could a boy like you render?' the smith replied.

'If the dog had a pup, I will bring it up to be just like its father. Until then, I will take the dog's place. I will be the hound to protect the lands and herds and flocks.'

'That is a good judgement,' Conchobhar said.

'I could have given no better myself,' said Caathbhadh the judge. 'Why should not Cu Chulain, the Hound of Culan be your name because of this?'

'I prefer my own name,' the boy answered.

'Do not say that, for all the men of Ireland and Scotland will hear this name and be full of that name.'

'Then I will take that name,' the boy answered.

And every man in Ireland and Scotland knew the name of Cu Chulain, because he killed the hound of Culan the smith.