The Iron Gronckle

The Iron Gronckle is the second episode of Dragons: Defenders of Berk and the twenty second episode of the Dream Works Dragons telivision series. It was first aired on Cartoon Network September 26, 2013. The plot focuses mainly on Meatlug and Fishlegs as terrible trouble arises when Meatlug eats magnetic rocks.

Plot
Meatlug ingests magnetic rocks, causing destruction throughout the town.

Trivia

 * This is the second episode in a row that there has been no narration.
 * This is the first episode that the Outcasts appear without Alvin.
 * One of the Vikings names is Gunnar. This is the same name for those who had Astrid, and chose boy, on the Viking Personality Test that was on the Legend of the BoneKnapper Dragon DVD.
 * Hiccup's new shield is completed.
 * This episode breaks the fourth wall as water drops go on the camera as the Outcast ship sinks.
 * This episode is loosely based off How to Break a Dragon's Heart, when Toothless ate Stoick's "magic" stone and would stick to metal objects.
 * Stoick did not appear in this episode. This is the first time he didn't appear in the series.

Source
http://www.imdb.com/tvgrid/2013-09-19/TOON/?start_date=2013-09-26&channel=TOON#