Ikoria: Lair of Behemoths

Majestic Auricorn | Creature | Unicorn | Mutate {3}{W} (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.) Vigilance Whenever this creature mutates, you gain 4 life. | Jonathan Kuo

Patagia Tiger | Creature | Cat | Flying When Patagia Tiger enters the battlefield, target Human you control gets +2/+2 until end of turn. | Micah Epstein

Yorion, Sky Nomad | Legendary Creature | Bird Serpent | Companion — Your starting deck contains at least twenty cards more than the minimum deck size. (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.) Flying When Yorion enters the battlefield, exile any number of other nonland permanents you own and control. Return those cards to the battlefield at the beginning of the next end step. | Steven Belledin

Jegantha, the Wellspring | Legendary Creature | Elemental Elk | Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (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.) {T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs. | Chris Rahn

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