Alvin The Treacherous (Voiced By Mark Hamill) is the leader of the Outcast Tribe and the main recurring antagonist of Dragons Riders of Berk. Suffering from the same issues Berk had at the start of the feature film, he invaded Berk, seeking to capture the "Dragon Conqueror" by taking hostages to trade. When he discovered from Hiccup and his friends that dragons are able to be tamed and domesticated, Alvin constantly develops plans to kidnap Hiccup in order to use the dragons for his own purposes, primarily to take control of other lands by threats and force. In the season 1 finale, Alvin captures Hiccup and Toothless with Mildew's help. Although Hiccup and Toothless escaped with the help of Stoick, Astrid and the others, Mildew managed to give Alvin information on how to tame dragons. At the end, he tames a Whispering Death dragon. He Now travel The World Searching for Hiccup And The gang to Destroy Them, Along With The Other Villains, Mildew, Savage, And Dagur The Deranged. However, at the end of the Series, Alvin has repent his way and becomes an ally of Berk.
- Alvin Is The Main Antagonist Of Hiccup's Adventures Series.
- He Will Become Jaden and Jeffrey's Enemy in Jeffrey, Jaden & Friends' Storm Adventures of Dragons: Riders of Berk.
- Alvin will return for revenge in Jeffrey, Jaden & Hiccup get Spirited Away.
- Alvin was the only villain that little Xion was always afraid of. After he reforms however, those fears have vanished for good.
- After Alvin has Turned into an ally and amends with Stoick, He becomes an ally to Berk.