The Lich King: At the start of the game, the leftmost card is suffled into the deck and replaced with the 1 mana boss card for the match

[troggnostupidhs]

srd_27 At the start of the game against Lich King, now you'll see his left-most card got transformed to his 1-mana spell. And the original card was shown shuffled to his deck Guess recent patch somehow unhide the animation for this