This is not a reference to Zetsubou Sensei.
It is a reference to the drawing of Spoo (スプー) which appeared on Together with Mom (おかあさんといっしょ).

For the hilarious original drawing song, watch https://youtu.be/ML1ndKy5fRE?t=32s

Awalker said:

This is not a reference to Zetsubou Sensei.
It is a reference to the drawing of Spoo (スプー) which appeared on Together with Mom (おかあさんといっしょ).

For the hilarious original drawing song, watch https://youtu.be/ML1ndKy5fRE?t=32s

ok, I didn't knew that... the first thing that came to mind were the drawing songs from Zetsubou Sensei so I tagged these like that but it seems those also were parodies of that video

I love how you can see the male host's composure break in the video, when he finally looks up from his drawing and sees how badly the lady has drawn hers.