Chainers Edict, Consuming Vapors, Custodi Lich, Dead Drop, Devour Flesh, Diabolic Edict, Gatekeeper of Malakir, Geths Verdict, and others are among just a few of the spells that can cause an opponent to sacrifice a pro-black critter
Free's views on the topic seem to look at intent and degree when defining a scalper
Rattata can be obtained from Shining Revelry pack in the Shining Revelry set
Vraska's ultimate gets an opponent to nine poison counters, and a single attack or proliferate will finish things off from there
Ransom Note Ransom Note is a 1-mana clue that can be used for other finalities, including goading a creature or cloaking the top card from your library
It costs X +3, and when played you gain X life and draw X cards