Ikoria: Lair of Behemoths

Voracious Greatshark | Creature | Shark | Flash When Voracious Greatshark enters the battlefield, counter target artifact or creature spell. | Mathias Kollros

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

Keruga, the Macrosage | Legendary Creature | Dinosaur Hippo | Companion — Your starting deck contains only cards with mana value 3 or greater 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.) When Keruga, the Macrosage enters the battlefield, draw a card for each other permanent you control with mana value 3 or greater. | Dan Scott

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