Howlfiend is a Warlock minion card (rarity: common) that belongs to the "Knights of the Frozen Throne" set, which was released on 10.08.2017 and is one of initially 135 cards. The artist of this card was Konstantin Turovec, who also made 143 other artworks for Hearthstone.
The card costs 3 mana, has 3 attack and 6 health, and its card text reads: "Whenever this minion takes damage, discard a random card."
The flavor text of the card is the following: The problem is that he carries those cards in his mouth.
Based on 118 quiz answers, the card is easy to memorize: 91% of them were correct. The question on “Name” is answered correctly most often (100%), the one on “Cost” least often (76%). An answer takes 5.1 seconds on average.