Mana Wyrm is a common Mage minion card that belongs to the "Legacy" set. The artist of this card was Blizzard Cinematics, who also made 1 other artworks for Hearthstone.
The flavor text of the card is the following: These wyrms feed on arcane energies, and while they are generally considered a nuisance rather than a real threat, you really shouldn't leave them alone with a bucket of mana.
The card is easy to memorize with 90.91% of correct quiz questions.