Fishlegs is quite the opposite to his book counterpart. He is very big and chubby and often spouts off information about dragons whenever he can, usually as if he were describing the stats of a creature in an RPG. This annoys the other teenagers frequently during their sessions at Dragon Training.
Later, Fishlegs learns how to fly on a dragon from Hiccup and ends up flying and owning the Gronckle used in Dragon Training, which he later names Meatlug. His analysis of dragons becomes invaluable for the rest of the Vikings when he identifies the characteristics and weaknesses of the Red Death.
Fishlegs is among the riders who participate in Dragon Racing shown at the beginning of the film. He cheers as Meatlug picks up a sheep, but it is taken by Snotlout, who then tosses it to Ruffnut. When a black sheep is launched, Meatlug catches it before Stormfly can. Fishlegs congratulates Meatlug for catching the black sheep before tossing it to Ruffnut, but Astrid takes the black sheep and wins the race.
Later, Fishlegs and the other Dragon Riders, led by Astrid (since Hiccup is with his long-lost mother), capture Eret, Son of Eret, so that they can go to Drago Bludvist, only to be captured upon arrival. He participates in a battle against Drago's forces, during which Hiccup's father Stoick is killed by a mind-controlled Toothless, under hypnosis from Drago's Bewilderbeast. Fishlegs's Meatlug is taken by Drago's Bewilderbeast, the new alpha, while he and his companions mourn the death of Stoick. After listening to Hiccup's speech that they are going back, Fishlegs and the others ride back to Berk on baby Scuttleclaws.
After Hiccup and Toothless return the dragons back to their side and defeat Drago and his Bewilderbeast, Fishlegs celebrates victory with the others. He then happily reunites with Meatlug, hugging her affectionately, and celebrates Hiccup's coronation as the new Chief of Berk.
In the second movie, Fishlegs is wearing the same furry outfit only this time with furry armbands, a belt with pockets and a helmet with something that resembles little Gronckle ears or wings. He has grown a thin beard. He also grown heavier weight since the past five years.
Abilities and Skills
Fishlegs is probably one of strongest and smartest, but also one of the most cowardly and quietest members of the Academy. Despite his flaws, he still a valued member of the gang.
Intelligence and Builder: Fishlegs has proven several times, especially in the first film and in the series whenever a new species of Dragon appeared, that he has a great knowledge on dragons. However, where Hiccup learns from experiences, Fishlegs rather learns from books. He even thought of hand signals, knows why Changewings were looking at the boat because of Snotlout having the fourth egg, using different collars on dragons for different islands to study their territory for specific reasons, figuring out why the Flightmare comes every ten years but mostly his dragon was the one to figure it out, and taught some ideas for his Meatlug to improve her combat ability to learn new fighting skills that were shown all great success. He even build his own Viking ship but faild for to Meatlug getting sea sick and realase lava out of her mouth.
Strength: It was revealed that when Fishlegs gets angry, he will go berserk, successfully defeating enemies and intimidating people. This is probably based on the books, where Fishlegs was half Berserker, half Murderous. He was also able to tackle-hug Meatlug in Gift of the Night Fury, (though Meatlug might not have expected it, so she probably didn't hold her ground much.)
Dragon Training and Riding: So far, Fishlegs has trained two dragons. His Gronckle, Meatlug and a Terrible Terror named Iggy. However, he isn't the best Dragon Rider. He flew on Toothless once, though he was very afraid of doing so being so fast that he wasn't used to it. However, he was able to overcome his fear in order to save Meatlug. He has multiple useful ideas for Dragon Training methods, as he was the one who invented the hand signals. He is also quite skilled in Dragon Calls. He the only one thought of great training ideas for Meatlug to improver her combat ability to gain amazing skills which all have become success. And using pictures for Iggy to know which object to get for him.
Navigator Skills: Fishlegs shown to be the best for navigating islands and locations. As he shown this skill as he was able to recognize different dragons locations on certain collars. Also able to recognize their surroundings around Berk.
Speed: He shown for his heavy weight he able to run fast to catch up to the teens when he afraid.
Endurance and Stamina: In the first film he shown to be able to take Meatlug weight on him when she fall and his stamina for heavy weight teen he able to run long distance with out showing anytype of difficulties at all.
- In the books, Fishlegs is even skinnier then Hiccup, but in the movie, he's clearly a heavy-set teen.
- Fishlegs is the only one in the movie that doesn't seem to actually make fun of Hiccup besides Astrid (who still criticized, scolded, threatened and harmed Hiccup on separate occasions throughout the film).
- Even though he receives the Gronckle Iron sword from Gobber at the end of The Iron Gronckle, he doesn't use it after that episode.
- Fishlegs has Binge Eating Disorder.
- He is the Berk Dragon Academy's Boulder Class Dragons expert.
- Of all the main characters during Defenders of Berk, Fishlegs had the most episodes that focused on his character development.
- In Dawn of the dragon racers, he also seems to creep out Hiccup when he appears from behind him like a ghost.
- Fishlegs will meet Thomas, Twilight and their friends in Thomas and Twilight Sparkle show How to Train Your Dragon.