Scarecrow and Harley Quinn (Batman: Arkham Asylum)

Nerdiest Halloween Costumes

(via)

 

Trevor (GTA V)

The Best Nerdy Costumes of 2013

(via)

 

BMO and Ice King (Adventure Time)

Nerdiest Costumes

(via)

 

The World of Old Microsoft

Nerdiest Halloween Costumes

(via)

 

DJ Ruby Rhod (The Fifth Element)

Nerdiest Halloween Costumes

(via)