Although they didnt all make the rankings, these Mistform cards from Legions pretty much all have these type-altering abilities, whether directed at themselves or at other creatures
He's got a very fun effect, too, which essentially resurrects the creatures he kills as thralls that are 'bound' to him -- when the Krovikan Vampire dies, so do the resurrected minions
And then other times, I like tapping lands, finding awesome synergies and combos and using them
He is the key removal piece in Sengoku's (OP16-060) Three Admirals Navy deck
If your time is worth anything to you and you're sitting on thousands of commons, this is probably the move
we even have The Meathook Massacre and Invasion of Fiora Flip as our boardwipes