Astrid owns a custom made axe that acts as her main weapon as an adult.
It is unclear when Astrid switched out her old axe as she appears to still be using it during the events of Dragons: Race to the Edge.
Her new axe, however, makes its first appearance in How to Train Your Dragon 2 when Astrid attempts to threaten Eret and his men after she and Hiccup land on Eret's boat. Prior to this scene, her axe appears to be strapped to Stormfly's saddle and Astrid has to resort to using a stick as an alternative weapon.
After Hiccup throws a net over Astrid, he ends up taking her axe away from her and hands it over to Eret. Astrid has her axe with her up until she and the others riders get captured by Drago Bludvist and his men. However, she was shown to have reclaimed the axe in Burning Midnight.
It is implied that Hiccup crafted Astrid's new axe and made her a saddle which is accommodated to hold an axe in place during flight.
Unlike her old axe, which Astrid inherited from her mother, this double edged axe has a longer haft/handle covered in fur and two metallic dragon heads on each side of the knob. One of the heads appears to resemble a Deadly Nadder while the other looks like a Night Fury.
The initial designs also included a leather strap tied to the knob.
- Astrid's new axe matches her new saddle.
- It's possible Hiccup gave Astrid this new axe as a gift.
- In Burning Midnight and Dragonvine Astrid has a flaming axe matching Hiccup's flame sword.