I’ve been trying to remember all the childish songs from my youth so I can teach them to my nephews. Aside from having extra dessert at lunch time, the easiest way for a kid to make new friends is to teach them an inappropriate song or two.
Some of the songs I’ve remembered, though, might get him into a little too much trouble at school. They also make me think that children are psychotic. Here’s one I remember happily singing at recess:

Joy to the World!
The teacher’s dead! We barbecued her head!
What happened to her body? We flushed it down the potty!
And ’round and ’round it went! … etc.

I might just keep that one to myself; it gives me visions of Nancy Grace shrieking newspaper headlines.

If you can think of any kindergarten-era songs you’d like me to share with my nephews, please let me know in the comments. I want to make sure they make the most of elementary school. Post titles, lyrics, links to YouTube videos, whatever. Here’s the best video I’ve found so far: