The Storm in Fortnite Save the World is the cause of the monsters. The Storm spawns the Storm King who is a monster. (See below) The Storm makes a virus affect humans, making their skull come out of the head. That's why the back long is a deflated human head.
The Storm King[]
Released in Season 7, the Storm King is the final and toughest boss of the Save the World game, and eventually moved on to Fortnite: Battle Royale. While your squad along with the director and Ray to help you, it's still a challenge. The boss may not have a lot of heath as you may think, but it's attack damage is really high. Upon death, a giant purple cube (as shown in Season 6) comes out of the Storm King along with 4 other valuable items used for Save the World.
