There have been several theories, with some carrying significant weight, about what new weapon Thor will be wielding in Avengers: Infinity War. The character lost Mjolnir at the hands of his evil sister Hela, goddess of death, last year in the Marvel Cinematic Universe and it was unlikely that he would resort to protecting mortals with only his bare hands.
It was earlier established that the mystical hammer could not be reconstructed in time for the clash against Thanos. The debate quickly moved on to Thor wielding Jarnbjorn, a gigantic battleaxe from the comic books, that was teased in the original concept arts for the movie as well as with the recent lineup of action figures from Marvel.
However, another leak has surfaced on the weekend to claim something else entirely for the thunder god. If the box-art of the unreleased toy is legitimate, Thor could be swinging Stormbreaker in Avengers: Infinity War.
— Marvelous Realm (@MarvelousRealm) February 12, 2018
Similar to his other arsenal, Stormbreaker is also from the source materials. The hybrid weapon is half hammer and half axe. It is made of the same Uru metal as Mjolnir and hence, nearly indestructible. The weapon also features much of the same properties and powers–only the worthy individual can lift it.
It is possible that Thor gets Mjolnir back during the two-part saga. The weapon is, after all, a signature part of his attire. On that note, Thor will not be the only one to upgrade his arsenal in the movie. Captain America will also be wielding a new shield.
Avengers: Infinity War will open in theaters on May 4, 2018. The untitled sequel, presently dubbed Avengers 4, is slated to premiere on May 3, 2019.