I can just imagine when you were in school, sitting in a classroom, looking so cute, while your mind was creating mischief - random and evil inventions, diabolical fates imagined for your most-hated teachers, frightening horrors plotted out for all and sundry !!
And the things you make the poor man eat - eels, and now pork pie. What next - steak & kidney pie? Liver? *shudder*
And I believe this tale - Severus Snape is capable of anything! Even the accidental creation of the tortoise.