Ikoria: Lair of Behemoths

Frost Lynx | Creature | Elemental Cat | When Frost Lynx enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step. | Ilse Gort

Phase Dolphin | Creature | Elemental Whale | Whenever Phase Dolphin attacks, another target attacking creature can't be blocked this turn. | Lie Setiawan

Sea-Dasher Octopus | Creature | Octopus | Mutate {1}{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.) Flash Whenever this creature deals combat damage to a player, draw a card. | Chris Seaman

Thieving Otter | Creature | Otter | Whenever Thieving Otter deals damage to an opponent, draw a card. | Jakub Kasper

Wingspan Mentor | Creature | Human Wizard | When Wingspan Mentor enters the battlefield, put a flying counter on target non-Human creature you control. {2}{U}, {T}: Put a +1/+1 counter on each creature you control with flying. | Sidharth Chaturvedi

Jubilant Skybonder | Creature | Human Wizard | Flying Creatures you control with flying have "Spells your opponents cast that target this creature cost {2} more to cast." | Jesper Ejsing

Slitherwisp | Creature | Elemental Nightmare | Flash Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life. | Yigit Koroglu

Lore Drakkis | Creature | Lizard Beast | Mutate {U/R}{U/R} (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, return target instant or sorcery card from your graveyard to your hand. | Lucas Graciano

Rielle, the Everwise | Legendary Creature | Human Wizard | Rielle, the Everwise gets +1/+0 for each instant and sorcery card in your graveyard. Whenever you discard one or more cards for the first time each turn, draw that many cards. | Yongjae Choi

Lutri, the Spellchaser | Legendary Creature | Elemental Otter | Companion — Each nonland card in your starting deck has a different name. (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.) Flash When Lutri, the Spellchaser enters the battlefield, if you cast it, copy target instant or sorcery spell you control. You may choose new targets for the copy. | Lie Setiawan

Trumpeting Gnarr | Creature | Beast | Mutate {3}{G/U}{G/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.) Whenever this creature mutates, create a 3/3 green Beast creature token. | Aaron Miller

Vadrok, Apex of Thunder | Legendary Creature | Elemental Dinosaur Cat | Mutate {1}{W/U}{R}{R} (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, first strike Whenever this creature mutates, you may cast target noncreature card with mana value 3 or less from your graveyard without paying its mana cost. | Zack Stella