Gyruda, Doom of Depths (Promo Pack) [Ikoria: Lair of Behemoths Promos]

Companion — Your starting deck contains only cards with even converted mana costs. (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 Gyruda enters the battlefield, each player mills four cards. Put a creature card with an even converted mana cost from among the milled cards onto the battlefield under your control.