Boy Next Door is an ultra-rare big brother from the New Kids Club.
- He has two sisters named Lil Baby Next Door and Baby Next Door
- He has a little brother named Lil Boy Next Door
- He has a dog named Puppy Next Door
Boy Next Door has dark brown skin, brown eyebrows, half black and half white hair in a flat-top style, and indigo eyes. He wears white and blue dungarees which aren't secured at the top, and show his multi-coloured t-shirt with mismatched patterns on it. He has yellow socks and white shoes with a pink and blue top rim, and pink soles.
He comes with a blue bottle which has white zigzags on it, a white handle, a fluorescent yellow lid, and a fluorescent orange strip around the bottle with a circle in the middle which reads "POP".
- He may be based on the saying "Boy Next Door".