Borg, the Greed Stricken

Flying, trample
Borg, the Greed Stricken enters the battlefield with X -1/-1 counters, where X is the number of nonland permanents an opponent controls.
At the beginning of your upkeep, remove a -1/-1 counter from this card and tap it: Target opponent sacrifices a nonland permanent. If they cannot, they lose 6 life and you draw a card.