Fairy Tail Episode 12: Moon Drip
Episode 12 of 175 of Fairy Tail, aired January 3, 2010, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Natsu, Lucy, Gray, and Happy uncover a plot to release a demon that wrecked havoc years ago and was only stopped by Gray's former teacher who sacrificed herself to seal away the beast. They meet up with the wizards responsible and a fight breaks out between Gray and a masked wizard who turns out to be Lyon, a person from Gray's past. Meanwhile, Erza makes her way to the island.