Potion's Class

I don't quite see ...

the reasoning behind a potions class without Slytherins.

So, if you want a Potion's class ... apply to be sorted into my house.

For now, I will give a brief introduction to

GRAWNS (guh-raw-ons) [pictured below]

Write at least of paragraph summarizing grawns. 

    Where to find that information?  I see you didn't buy your schoolbooks. (!)  Fine, then go to the Library.

Professor Snape