- "Vikings are strong, tough, and courageous. But courage is a funny thing, many are born with it. For some, it's a never ending struggle and for others, well . . . they just don't know enough to be afraid."
While skipping lessons at the academy, Fishlegs and Meatlug discovered a strange, color-changing gem. Several more gems are soon discovered. When Hiccup learns that the gems are in fact the eggs of the acid-spewing Changewing dragon, the kids must scramble to retrieve the eggs from throughout the village before the Changewings destroy Berk.
At the Academy, Gobber is teaching the Riders how to defend themselves on their own without the help of their dragons. He pairs up each of the Riders to battle each other. First the twins fight eachother. Then he has Astrid and Hiccup have a try at it. Hiccup insists it's not a fair match and is then quickly pinned to the ground by Astrid. Unable to move, he plays dead at Gobber's advice. After that, Gobber tells it's Snotlout and Fishlegs' turn, Snotlout feels confident he'll turn out to be the victor, however, Fishlegs is nowhere present in the arena.
On a small rocky island, Meatlug and Fishlegs are relaxing out in the shore, ignoring the training exercise. After Fishlegs signs a song about Meatlug, he tries to get her to hug him at the end. Insteads, she walks away and digs for something in the sand, and what they discover surprises Fishlegs. Hours later at night, Fishlegs return to Berk, where the Riders notice a glowing figure in his satchel, Fishlegs reveals what they discovered, which surprises the others.He eventually releases it to the people of Berk in the Great Hall. Gobber tells him that he is holding a Stone of Good Fortune, and one of his once mute great relative was able to discover one of them (causing him to talk again but wouldn't shut up about his discovery). He reveales that it possesses powers that brings good luck to whomever finds it. This causes everyone in the Hall to claim the stone, causing a frenzy where people wants to take the stone from Fishlegs. Luckily, Stoick arrives to control the crowd and tells them the stone is owned by Fishlegs and it's up to him whether to give it or not, so the crowd bargains their wealth to Fishlegs in desperation, even one Viking mother trades her own son, just in exchange for the need for good fortune.
Fishlegs is bombarded by pressure as the crowd keeps bidding higher prices of their wealth in exchange for the stone, so Hiccup tells Fishlegs to come outside to avoid the crowd. Snotlout is disappointed by Fishlegs passing up all the great possessions the crowd would offer and asks Fishlegs what does he want for the stone to be traded, but Fishlegs declares no one can have the stone. Snotlout reminds him threateningly that if he wants something he'll take it, but Astrid backs him up and defends Fishlegs. After that, Fishlegs and the others leave, leaving Snotlout to declare that he'll take it no matter what.
Moments later, the Riders goes with Fishlegs when he decides to return the stone to where they first found it. But when they stumble through the island, they found dozens of the same stones lying in nests in the branches of trees. They quickly realize that it's not a stone of good fortune, but a dragon egg. Fishlegs then becomes depressed because he took one of the eggs from a mother dragon, Hiccup tells him that returning the egg to it's mother will redeem him, and that they must quickly leave. Upon returning the egg, they are pursued by the mothers seeing them as a threat. Upon finding that these dragons are invisible, Hiccup, Astrid, and Fishlegs, and manages to escape narrowly, and head home. Meanwhile, Snotlout is revealed to have followed them and is trying to get one of the eggs which he still thinks are stones of good fortune, without either of the Riders knowing. At the Great Hall, Hiccup, Astrid and Fishlegs learns that the dragons that pursued them are Changewings, dragons who can blend in into any environment causing them to be invisible, and has a unique attack by spitting acid at it's victims, Hiccup notices that these dragons have no image on the Book as it is barely examined closely. Suddenly, the Twins arrive holding a Changewing egg, thinking that it's a stone of good fortune. That stuns the Riders, and when Astrid tries to take it away from them, they refuse and flees the scene, and reveals that they traded with Snotlout.
Outside, Snotlout have stolen three of the eggs and quickly solds it to the vikings; the last one is recently claimed by Bucket. After selling all three eggs, Snotlout packs up all of his loot, including Gustav. Hiccup, Astrid and Fishlegs arrive too late to get Snotlout to return all the eggs, even though Snotlout is informed the stones are dragon eggs, he tells them he can't do anything now as he has distributed the eggs to it's customers, and he leaves with all of his loot. Fishlegs begins to think that it's all his fault, that he caused all this, but Hiccup tells him it doesn't matter now as they have to find all the eggs so they can fix everything.
Meanwhile, the Twins are attempting to see the powers of the stone by putting it to the ultimate test. As Tuffnut stands into position in a cliff, where down below is a pit of Fireworms, he requests Ruffnut to kick him as he believes the stone will make him invulnerable. When Tuffnut plummets, he is luckily rescued by Astrid, where Hiccup and Fishlegs' tells them the egg's origins. However, the Changewings arrive at the scene. The Riders witness it's incredible ability to blend in, the Changewings attack viciously, and finally claims the egg from Tuffnut. Hiccup and Fishlegs witness that the Changewing mothers worked as a team just to save that one egg, realizing that the Changewings will not leave until one by one they have their eggs, even if they have to tear apart Berk.At their homestead, Hiccup informs Stoick of the impending siege of the Changewings. Hiccup recommends that the villagers be evacuated from the area until the eggs are returned, though Stoick refuse retreat and is confident that they'll stand their ground and fight the Changewings, despite it's ability to camouflage. Suddenly, the Changewings begin their violent search for their eggs where they wreak havoc on the town. Stoick witnesses the Changewing's ability to blend in and disappear in front of them. Stoick orders Hiccup to find the eggs as they'll take care of the Changewings. Stoick and Gobber fight off one Changewing but realizes it to be difficult to take them all out as they keep disappearing and reappearing all at once. Stoick finally declares a full evacuation at the harbor.
Meanwhile, the Riders are successfully managing to return the eggs to the Changewings from Bucket and Mrs. Larson. At the harbor, frantic and panicking villagers run desperately with all their possessions at the harbor. Hiccup, Astrid and Fishlegs arrive to tell Stoick and Gobber to abort the evacuation plan as they managed to return all the eggs, but Gobber points out why aren't the Changewings leaving yet, as they discover four Changewing mothers lurking near the harbor. They claim there was only three eggs, they also notice the Changewings targeting the ship, confusing them. But Fishlegs concludes it's not the ship, but another egg inside it whom he suspects Snotlout has another one kept for himself, he tells Hiccup and the others to keep the Changewings at bay as a now violent Fishlegs attempt to take the egg from Snotlout.
Fishlegs confidently confronts Snotlout and demands to give up the egg, Snotlout continues to mock him as if he is still a weakling. As a result, Fishlegs rages violently through Snotlout strongly tipping over all of his heavy loot, he looks for it but finds the egg not there. He then confronts Snotlout, where now frightened by him, threatening him he can do whatever he want to him but separating an egg from a dragon mother is one thing he cannot allow. Suddenly, Meatlug searches for the egg and quickly finds it. As Fishlegs grabs the egg he asks Snotlout to dare object, Snotlout stands down and watches Fishlegs and Meatlug take the egg back.
Moments later, Fishlegs calls for the Changewing mothers as he tells them their last egg is here. He continues to call for them in the now ghost town part of the village, where no one would dare to enter alone. Fishlegs then finds himself surrounded by the Changewing mothers, before giving the egg, Fishlegs wholeheartedly pledges in his life to keep anyone from stealing their eggs if the Changewings decide to spare him. When the Changewing mother claims the egg, all of them attempt to seemingly finish off Fishlegs, but at the last moment, Fishlegs realizes the Changewings spared his life and disappears from Berk, after that he passes out.
The next day at the Academy, Fishlegs takes pride of his close encounter of the Changewings last night and informing all about it to Hiccup, where they draw finally an image of it in the Book of Dragons, as Fishlegs makes sure Hiccup get the exact details of it's physical appearance. Fishlegs expresses his desire to find one in order to study it, but Hiccup says it's better that they train it. Just then, Gobber calls Fishlegs for his hand-to-hand combat confrontation with Snotlout.
Fishlegs courageously steps in for the duel, where Snotlout is a bit concerned after what he witnessed with Fishlegs last night. As the fight commences, the two hardens for combat as they come face to face to see who will prevail.
- "Having courage isn't the same as having no fear. It's about being afraid and pushing forward anyway, whether that means saving a baby dragon, protecting those you love, or giving a special someone the butt-kicking they so richly deserve."
- In the movie, there was an image of a Changewing in the Dragon Manual, but in the episode, the book does not have a sketch, as no Viking had ever successfully examined it.
- This episode is the start of where the Changewings come into play in the TV series, as Hiccup becomes interested in finding and training a Changewing near the end of the episode to further learn more about it.
- It is said by Stoick that for the first time, the inhabitants of Berk have never retreated the island to anything.
- Ruffnut references the events in Portrait of Hiccup as a Buff Young Man by saying "You (Tuffnut) remember what just one of those things (Fireworms) did to you?"
- This is the first time in the series that Fishlegs shows Berserk qualities, like his book counterpart.
- Fishlegs was the only one to come face-to-face with four of the Changewings and was able to describe their physical appearance to Hiccup at the end.
- This is the first episode in which Meatlug reveals the qualities of a dog-keen sense of smell and digging up objects.
- The Changewing eggs glow and change color, as if it were a crystal ball.
- In Fishlegs' song he rhymes the name of his dragon, Meatlug, with the word "Sea-slug," which is the name of Dogsbreath's Gronckle in the books.
In the beginning Hildegard's mother is seen, as well as Mrs. Larson and her son Gustav. However, when looking for the Changewing eggs, Mrs. Larson has Hildegard, and calls her her baby. This led many to believe that Hildegard and Gustav are siblings. But Hildegard's mother and Mrs. Larson have different character designs, so this was a goof in the episode.
- Jay Baruchel as Hiccup Horrendous Haddock III
- America Ferrera as Astrid Hofferson
- Nolan North as Stoick the Vast
- Chris Edgerly as Gobber the Belch
- Christopher Mintz-Plasse as Fishlegs Ingerman
- Julie Marcus as Ruffnut Thorston
- T.J. Miller as Tuffnut Thorston
- Zack Pearlman as Snotlout Jorgenson