The legend is that there was a giant who made a living by carrying travellers across a river; one day a small child asked for a lift and the giant laughed and swung him up on to his shoulder and started confidently across, but his light burden soon became heavier and heavier until he could hardly manage to stagger to the opposite bank. And the child explained that, in carrying him, the giant had also been carrying all the sins of the world; and gave him a name (he'd never had one before):
Christopher!
I agree that the kind of Pieta image would be creepy: this, however, is quite cute.