This is me saying that “I run the game”, and in this case, the game is Jumanji.
Outside of the box like zombies: This is a simple statement saying that I am “outside of the box (of normal creativity)” similar to how zombies are outside of their caskets; Also, Jumanji is a movie about a mythical board game that comes in a box
Head full of dread like Samedi: Saying that I have dreads like usual depiction of Baron Samedi, the voodoo god of death