Hiya! I just discovered this combo while making a deck. Its Kelpie/Pet Toad
+ Draco + 4 Privet Drive
It goes like this:
Play a 4 Privet Drive then, next turn, play a Pet Toad/Kelpie or both.
While doing this, use Draco's power to remove all cards from their hand except
for spell cards. So, thats all they'll have in their hand and with 4 Privet
Drive, they won't be able to use them anyway. Even if they solve it, those
spells will just hit Kelpie/Pet Toad.