Ikoria: Lair of Behemoths

Vivien, Monsters' Advocate | Legendary Planeswalker | Vivien | You may look at the top card of your library any time. You may cast creature spells from the top of your library. +1: Create a 3/3 green Beast creature token. Put your choice of a vigilance counter, a reach counter, or a trample counter on it. −2: When you cast your next creature spell this turn, search your library for a creature card with lesser mana value, put it onto the battlefield, then shuffle. | Lius Lasahido

Nethroi, Apex of Death | Legendary Creature | Cat Nightmare Beast | Mutate {4}{G/W}{B}{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.) Deathtouch, lifelink Whenever this creature mutates, return any number of target creature cards with total power 10 or less from your graveyard to the battlefield. | Slawomir Maniak

Brokkos, Apex of Forever | Legendary Creature | Nightmare Beast Elemental | Mutate {2}{U/B}{G}{G} (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.) Trample You may cast Brokkos, Apex of Forever from your graveyard using its mutate ability. | Filip Burburan

Illuna, Apex of Wishes | Legendary Creature | Beast Elemental Dinosaur | Mutate {3}{R/G}{U}{U} (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.) Flying, trample Whenever this creature mutates, exile cards from the top of your library until you exile a nonland permanent card. Put that card onto the battlefield or into your hand. | Chris Rahn