When Hookfang is drawn to a female Monstrous Nightmare, Snotlout tries to break them up before he loses his best friend forever.

Hiccup, Toothless and the dragon riders rescue a wounded Speed Stinger and take it back to Dragon's Edge, unaware of the dangers that follow.

The dragon riders discover a lush island that turns out to be the home of the Deathsong, a massive, never-before-seen dragon that threatens to trap them forever.

Thinking he's allergic to his best friend Meatlug, Fishlegs gets hypnotized – and wakes up transformed into an invincible warrior known as Thor Bonecrusher.

When Dagur the Deranged captures young Gustav, it's up to Hiccup, Toothless and the dragon riders to get him back.

On an island that will make the perfect outpost, the dragon riders discover its indigenous residents are a mysterious new breed of dragon.

The Riders race to the home of the true King of Dragons. But the Flyers are already there, and they soon come face to face with the legendary creature.

Fireworm dragons invade Dragon's Edge, while Ruffnut and Tuffnut discover that they have an unexpected connection to the island.

As a Rumblehorn dragon wreaks havoc on Dragon's Edge, Hiccup seeks the help of Stoick – who forms an unexpected bond with the rampaging beast.

The dragon riders are surprised to discover who is behind recent attacks on nearby ships – and to learn exactly what the ships are.

A familiar face joins ranks with the dragon riders, but it's not an easy alliance, especially when Hiccup uncovers a shocking secret about the new member's true identity.

While rescuing the dragons from a fire in the stables caused by a powerful lightning storm, Astrid suffers an injury that leaves her blind.

Fishlegs and Meatlug liberate the Gronckles from a menacing new dragon that has encroached on their ancestral home, Dark Deep.

The Riders learn of Ryker's attack on the Edge and attempt to stop the Shellfire and keep the Dragon Eye from being reclaimed by the Hunters.

When the Flyers try to kill him because he's no longer useful, Viggo forces Hiccup to help him get revenge by stealing their Dragon Eye and lenses.

With the fifth lens in place, the Dragon Eye 2 unveils the apparent King of Dragons, and Fishlegs immediately knows what it is and where to find it.

During their search for the escaped Dagur the Deranged, Hiccup and the Dragon Riders discover a mysterious object—one that holds their destiny.

After months of planning, Hiccup launches an operation to capture the Dragon Eye from Viggo, only to find that someone else has beaten them to it.

Hiccup, Toothless and the dragon riders journey to Glacier Island in search of the Snow Wraith, a fearsome new dragon that holds the key to the Dragon Eye's mysteries.

Heather's brother Dagur shows up out of no where and asks Hiccup for help finding her. He wants to learn to ride dragons. Dagur sees Heather on the edge and goes the extra mile to protect her.

After Heather and the Flightmare have been captured by Viggo and the Dragon Hunters, Hiccup must hatch a plan to outwit the dangerous new enemy.

After Astrid makes an alarming discovery, her life comes to depend on a dragon everyone thought was extinct. Her pals race against time to find it.

While hunting for gemstones needed to complete the Dragon Eye 2, Hiccup learns an old friend isn't who he seems. Dagur faces a bully from his past.

While trying to take care of unfinished business, Hiccup and Toothless are lured into a trap. An unlikely rescuer comes to their aid.

When Hiccup and Toothless are kidnapped and Toothless is forced to fight other dragons for entertainment, the rest of the dragon riders must save them before it's too late.