He visit his cousins, seemingly with innocent intentions. However, it is later revealed that he actually owes some Dragon Hunters a significant amount of gold, and that he came to the Edge to steal a Dragon that can be traded in as a substitute for the gold.
Abilities and Skills
Strength and Fighting Skills: He had stated to have beaten Tuffnut many times as kids. Though at the same age, he shown to still take on Tuffnutt with out too much trouble but he wasn't able to flying on Barf and Belch's body in the air.
Acting: When Gruffnut was dressed as Tuffnut, he was able to trick most of the Riders, as he tried acting like Tuffnut. However, he gained suspicion from Ruffnut and was finally caught as Ruffnut knew that Tuffnut would not have acted the way Gruffnut did. While he has an almost identical voice, he is exposed when Tuffnut mentions events only he would know, while Gruffnut agrees with Ruffnut's decision, something Tuffnut would never do.
Intelligence: Gruffnut was able to trick most of the riders by making them think that he was Tuffnut and smarter then Tuffnutt to make him believe in his lies very easily.
Dragon Thieving: He tried and was at first successful to steal the dragons from their owners. He offered fish to Stormfly but was caught by Tuffnut, he tried to steal Barf and Belch but instead they crashed, and he was close to being able steal Hookfang and Meatlug, but thanks to Tuffnut's chicken, his plans failed.
Endurance and Stamina: He was able to take the attacks from Tuffnut from their fight with the addition of taking a hit from a mace and still being able to get back from falling from Barf and Belch and onto a Dragon Hunter on a ship.
- Gruffnut's name is the third time the Twins' names have been parodied: previously Tuffnut pretended to be "Buffnut the Berserker" while going undercover among Dagur's crew, and later Ruffnut makes a pair of dummies of themselves which she dubs "Stuffnut and Fluffnut".
- He is mean towards Tuffnut's chicken, who is the first one to have suspicions about Gruffnut (and later recognizes him disguised).
- Strangely Gruffnut looks exactly like Tuffnut, despite being a distant cousin, implying that most of the Thorstons look very much alike.
- Gruffnut is voiced by T.J. Miller (Tuffnut's voice actor) but with a much hoarser voice.