Ikoria: Lair of Behemoths

Blitz Leech | Creature | Leech | Flash When Blitz Leech enters the battlefield, target creature an opponent controls gets -2/-2 until end of turn. Remove all counters from that creature. | Nicholas Gregory

Chittering Harvester | Creature | Nightmare | Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Whenever this creature mutates, each opponent sacrifices a creature. | Grzegorz Rutkowski

Gyruda, Doom of Depths | Legendary Creature | Demon Kraken | Companion — Your starting deck contains only cards with even mana values. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} any time you could cast a sorcery.) When Gyruda enters the battlefield, each player mills four cards. Put a creature card with an even mana value from among the milled cards onto the battlefield under your control. | Tyler Jacobson

Back for More | Instant | | Return target creature card from your graveyard to the battlefield. When you do, it fights up to one target creature you don't control. (Each deals damage equal to its power to the other.) | Daarken