Eugene "Bling-Bling Boy" Hamilton is a recurring and main antagonist in the series who has a one-sided crush on Susan.
Bling-Bling is a gluttonous, out of shape pale boy with brown hair and blue eyes (though he once claimed they were hazel) and freckles on his cheeks. He wears an all white outfit consisting of a collared shirt, pants with yellow stripes on the sides and sneakers also with yellow stripes. He wears a gold necklace and knuckles with 3 "B"'s, hence his nickname.
Bling-Bling is usually villainous at times, though he will act friendly towards Johnny, mainly because he sees a bit of himself in the flame-headed boy. To this end, he'll team up with Johnny and his friends to defeat another villain. Although he is well aware Susan doesn't share his romantic feelings (even when she tells him to his face that she doesn't like him), he's very persistent and refuses to give up, making all kinds of inventions and schemes to win her over, even going as far as to blackmail her.
Deep down Bling-Bling Boy is insecure due to being fat and having buck teeth although in Phat Johnny, his weight and buck teeth actually help Bling-Bling Boy become successful as a hip hop star.
Although he wouldn't admit it, he craves human interaction and builds robots to cope with this, which Johnny claims is sad (Johnny's Big Dumb Sisters).
- As stated in Johnny vs. Bling-Bling Boy and The Return of Johnny X, he also attended the Porkbelly Institution of Technology, but was kicked out after his thesis ate Professor Slopsink's hand. He later was allowed to return to the Institute in Johnny's Big Dumb Sisters after aiding in preventing a nuclear crisis.
- His female counterpart is Glam-Glam Girl. She was only seen in Johnny Alternative.
- In Johnny vs. Bling-Bling 3, the only time Bling-Bling Boy stopped liking Susan was when he ate an anti-Susan love pill. Unfortunately, this backfires as he instead, falls in love with Mary. But it was mentioned by Susan that the pill will wear off about 30 days and Bling Bling will fall for Susan again.
- His last name was revealed and confirmed by Monty in Mush, Johnny, Mush.
- He had a green "BB" in season 1.
- However, it was used for green screen.
- In Johnny's Hungry Games, he's revealed to be allergic to bees.