Jix, Merciful Kong of Jötun

Haste

When this creature deals combat damage to a player, you may cast an instant or sorcery with a total mana cost less than or equal to its toughness from your library without paying its mana cost. You may pay additional costs but cannot pay alternative costs when casting this way and this ability does not trigger if you cast an instant or sorcery during your upkeep or main phase.

"The fabled skies of the Cruel Spine Tibes pulse once again."
—Clyde Romias, Duke of Abermord