Ikoria: Lair of Behemoths

Cavern Whisperer | Creature | Nightmare | Mutate {3}{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.) Menace (This creature can't be blocked except by two or more creatures.) Whenever this creature mutates, each opponent discards a card. | Antonio José Manzanedo

Obosh, the Preypiercer | Legendary Creature | Hellion Horror | Companion — Your starting deck contains only cards with odd mana values and land cards. (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.) If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead. | Daarken

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

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