The "weirdo" in the title refers to Eleven, the mysterious girl Mike, Dustin, and Lucas find in the woods.
Eleven lacks basic social understanding; she nearly undresses in front of the boys when given fresh clothes, prompting Mike to explain the concept of "privacy" and the bathroom. Chapter Two: The Weirdo on Maple StreetStranger...
Mike officially gives her the nickname "El," shortened from the "011" tattoo on her arm. The "weirdo" in the title refers to Eleven,
She places a figurine of the Demogorgon next to Will's piece to indicate he is being hunted by a monster. Secondary Storylines Full article: The Gothic Pasts of Stranger Things the mysterious girl Mike
A key moment in the episode involves Eleven using a board to explain what happened to Will.