This is a short video of a teacher erasing a picture of a cat that an unknown student drew on the whiteboard. SPOILER SPOILER SPOILER SPOILER SPOILER: it morphs into a penis drawn with non-dry erase marker. Admittedly, that's a pretty solid prank, and if I'd witnessed it in school I would have dropped out that very same day because there's no way any teacher is teaching me anything more important than that, not in a million years.
Keep going for the video, but there are even more on Youtube because kids these days value a quality education.
Thanks to RNT Mike, who agrees the possibilities for transforming whiteboard drawing pranks are truly endless. But mostly penises for sure.