Stoick notes that as chief, one doesn't just have to balance between being a leader and friends but also what is good for all of Berk.
At first it seems like Dagur wants to kill him as a trophy, but by "Cast Out", it sounds more like he wants to force Toothless to become his own dragon instead.
This is later used to fake a full-scale dragon attack without the kids needing to give verbal commands.
Justified because there's a massive weight difference between them, and he also pins her against himself for a better hold.
: Mildew, who hates dragons with a passion and tries to use any opportunity to get rid of them.
They're nevertheless very close, arguably the two of the three most accomplished riders in the series and share unusual green eyes, leading to the show implying that they're siblings, a for the ultimate reveal that she's Dagur's sister.