Olgoth, Phantasmal Terror

Olgoth, Phantasmal Terror enters the battlefield with X +1/+1 counters on it. Whenever Olgoth, Phantasmal Terror deals combat damage to a player, that player discards a card.
When Olgoth, Phantasmal Terror dies, choose one: -Target player puts the top X cards of their library into their graveyard. OR -Target player draws X cards.