Howlfiend is a common Warlock minion card 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 142 other artworks for Hearthstone.
The flavor text of the card is the following: The problem is that he carries those cards in his mouth.
The card is easy to memorize with 90.68% of correct quiz questions.
