As far as Norse mythology is concerned, no there is not a weapon that approaches the described destructive power of the Brahmastra or Brahmashirsha astra. The most famous weapons from Norse mythology is Gungnir, the spear of Odin, and Mjölnir, Thor’s famous hammer. Both weapon’s creations is described in the Skáldskaparmál in the Prose Edda. Both weapons were created by the Dark Elves/Dwarves after Loki comes to them to get out of a mess of his own making. While intending to have a new golden head of hair created for the goddess Sif to replace the hair that Loki had cut, the weapon Gungnir was also created in the process. Gungnir is described as “never stopped in it’s thrust”, incredibly well balanced and powerful, and gives impossible spear skill to the one who wields it. The spear also appears to serve as a ceremonial or magical tool of Odin. He is described in many sagas and tales of throwing his spear over enemies to “claim them” as well as several times instructing others to do the same over enemy armies. In Hávamál, Odin is also described as piercing himself with his spear, hanging himself and “sacrificing himself to himself” in order to discover the runes. Mjölnir is described being created by the Dwarves as well, though more meddling by Loki results in the creation of a shortened haft on the hammer. Mjölnir is certainly described as a incredibly powerful weapon, far more than Gungnir by comparison. The hammer is known to be able to destroy nearly everything it touches, level mountains and will return to Thor’s hand after he has thrown it. He uses this hammer to act as the principal defender of both humanity and the other Gods. He frequently comes into conflict with the Jötunn (also referred to as Giants in many modern texts), and battles then using Mjölnir. Overall these weapons still do not approach the description of the Brahmastra which is described as capable of destroying the entire world.