Dragons: Riders of Berk Season 7 Episode 12 - Searching for Oswald ... and Chicken Episode Title:Searching for Oswald ... and Chicken.Episode Description:The Berserker siblings continue the search for their father and though each failure only spurs Heather's obsession, Dagur is worried the search will lead to her doom. He asks for Hiccup's help in deciphering Oswald's diary, which contains a picture of a massive dragon skull that leads them back to Vanaheim. Meanwhile the twins, Snotlout, and Astrid search for Chicken, who has gone missing, and find she has started a new family with a wild rooster. The search for Oswald doesn't end on as happy a note, with Dagur only finding his remains and a last message to him and Heather, though he continues his father's work by helping the Sentinels defend Vanaheim from the rogue Grim Gnasher dragons, and leaves satisfied that his father passed proud.