Brilliant style.
Although I've seen a couple of other attempts at it, no-one's been as successful in making a mock-children's story with depraved material.
Your voice is excellent as is the simple tune you've used. I loved the way you played a version of the same song at the end, but with distortion added.
I liked the wee asides (Billy's father, Bees, fun fact) and the whole thing made me smile.
Well done on making such an excellent piece of entertainment and thanks for sharing it with us. :)
P.S. Since you asked - yep, I found the 'easter egg'.