Puzzle Box of Yogg-Saron is a Mage spell card (rarity: epic) that belongs to the "Saviors of Uldum" set, which was released on 06.08.2019 and is one of initially 135 cards. The artist of this card was Kagi, who also made 16 other artworks for Hearthstone.
The card costs 10 mana and its card text reads: "Cast 10 random spells (targets chosen randomly)."
The flavor text of the card is the following: "PUT THE BOX DOWN, RENO!"
Based on 90 quiz answers, the card is easy to memorize: 99% of them were correct. The question on “Cost” is answered correctly most often (100%), the one on “Card text” least often (96%). An answer takes 4.6 seconds on average.