Goblin Blastmage is a rare Mage minion card that belongs to the "Goblins vs. Gnomes" set, which was released on 08.12.2014 and is one of initially 123 cards. The artist of this card was Glenn Rane, who also made 19 other artworks for Hearthstone.
The flavor text of the card is the following: If you can't find a bomb to throw, just pick up any goblin invention and throw that.
The card is easy to memorize with 100% of correct quiz questions.