Marlon and Lisa Grennan trust the world's biggest pit bull terrier to 'babysit' their newborn son.They even let 12 stone Hulk - a dog which is a banned breed in the UK - to lick their tiny baby boy Jackson.It's the same way he got to know their eldest son, Jordan, who grew up with Hulk and other American pit bull terriers at their home in New Hampshire, USA.
Lisa, 25 told Daily Mirror:
"I have no worries with Hulk being around the baby. It's not a big deal.When we brought Jackson home Hulk was all over him.
"He was watching me while I cared for him and he would go and check on him when he would cry."He is the perfect protector and babysitter.He followed me around everywhere. We couldn't ask for a better dog."He really does love him and you can see it in his eyes."
Marlon's company Dark Dynasty K9s specializes in training elite protection dogs for the police, celebrities and billionaire clients worldwide.