Seal of Light is a common Paladin spell 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 Jason Chan, who also made 2 other artworks for Hearthstone.
The card costs 2 mana and its card text reads: "Restore 4 Health to your hero and gain +2 Attack this turn."
The flavor text of the card is the following: The walrus of Light restores EIGHT Health.
Based on 119 quiz answers, the card is moderately hard to memorize: 89.08% of them were correct.