Boy cuts knee, snail emerges two weeks later

Here is something you don't see everyday. So a little boy was playing outside and cut his knee. Boys do this all the time. But when weeks go by, and the cut hasn't healed, and the knee is still swollen, mom decided to check it out thinking maybe there is a pebble inside. After slicing open the cut, she discovers that it is not a rock, but a snail.