One of the best known and most widely reported "teachercide" songs goes back to at least the 1960s, but I imagine it goes well further back than that:
Joy to the world, the teacher's dead
we barbecued her head!
What happened to the body?
We flushed it down the potty!
And round and round it went,
and round and round it went
and rouuund and round and round it went
A somewhat lesser-known (ie, hasn't been on The Simpsons) variation goes:
Joy to the world, the school burned down
and all the teachers died!
We're looking for the principal
he's hanging from the flagpole
a noose around his neck, a noose a around his neck...