Dean Parker, of Middlesbrough, Cleveland, was playing with a friend when two young boys appeared walking the dog, a mastiff cross-breed. It leapt at the snowman and demolished it. The boys then started to rebuild it and as they did so, Dean was attacked.
His friend, Edward Davies, aged eight, tried unsuccessfully to pull the dog off. He then ran more than a hundred yards to seek help.
Dean's father, Stephen, went to his son's aid, but Dean was dead on arrival in hospital. He died from neck and head injuries.
Edward's father, Peter, a former soldier, who also rushed to the scene soon afterwards, described the boy's injuries as 'horrific'.
'I have done several tours of Northern Ireland, but never saw anything as dreadful as that,' Mr Davies said.
His own son was still in shock last night. He had said that the dog was 'almost as tall as Dean', who at about 3ft high was small for his age.
Inspector Michael Sedlatschek, of Cleveland Police, said it appeared that the dog went out of control.
Dean's mother, Elaine, said: 'Edward said the dog attacked the snowman they were building first. He ran off to get some more snow to repair it and he heard Dean shouting for him.
'He turned around and saw the dog savaging Dean. He ran back to try and pull the dog off but he just wasn't strong enough.'
Mastiffs are a large and powerful breed. The mastiff dog involved in the attack was being kept at a local police station last night while inquiries into the case continued.Reuse content