Boingo

Boingo is a minor antagonist featured in Part III: Stardust Crusaders.

Personality
Boingo demonstrates a very introverted personality, and is content to resign himself into a supportive role, using his stand to aid his brother Oingo, and later, Hol Horse (though he was more forced to do so than doing so out of his own will). Boingo was so shy that he struggled even to laugh and frequently stuttered. Initially he's shown to be very reliable on his brother, not doing anything away from him. Because of that, Oingo protected him from the world, afraid of how many bad people would take advantage of his little brother. They shared a really close relationship, working as partners and relying one on the other. He demonstrated a good side on him, as he considered the posibility of becoming a good guy.

Stardust Crusaders
Boingo is first seen reading from the comic book Thoth and then meets a friendly comic artist who offers to buy it from him. However, Oingo maintains that the book is not for sale and threatens the comic artist to stay away from Boingo. He then reads the comic and decides to wait four hours for the next bus to avoid the accident. The brothers then look into Thoth for the next prediction and realize that they were meant to poison the Joestar group's tea. Boingo stays in the shadows and witnesses Oingo's preparations to fulfill the prophecy. At the same time, Jean Pierre Polnareff lets a cigarette fall, which points to their restaurant.

Initially, the group decide to order tea, but a suspicious Joseph Joestar decides to order the unopened coke instead. This seems to prevent Oingo from poisoning the drink at first, but an angry customer reacts to the warm coke he was served, causing the Joestar group to order the tea that Oingo successfully poisons. However, right as the group is about to drink their tea, Iggy eats another customer's cake and causes the Joestar group to abandon their tea to take care of Iggy and leave shop, which makes Oingo and Boingo angry. Eventually, following Thoth's prophecy, Oingo punches a nerdy-looking stranger and frightens him into dropping his wallet, giving the two money and temporarily pacifying them for their failure.

Following Thoth's next prediction, Oingo then tries to make Jotaro eat a bomb that looked like an orange. However, Joseph and Polnareff return and Oingo is forced to disguise himself as Jotaro in order prevent them from attacking him. The disguise backfires and Oingo is dragged into the same car where he placed the bomb. Boingo becomes shocked after finding out the true meaning of Thoth's prophecy, that Oingo is the one who will fall victim to the bomb with Jotaro's face, and mentally begs for his brother to transform back so that their intended interpretation of the prophecy will come true. Regardless, Oingo accidentally steps on the bomb he set up, causing it to blow up and split his face in two. Boingo then arrives and resolves to defeat the Joestar group on his own, causing Oingo to become proud of his younger brother's growth. However, the man Oingo assaulted earlier returns with other thugs, who beat up the two brothers and send them to the hospital. Meanwhile, the real Jotaro returns from visiting the hospital, and, happening to be thirsty, picks out an orange to eat. After exiting the hospital, Boingo teams up with Hol Horse to avenge his brother (albeit only after Hol Horse had to resort to kidnapping Boingo). Boingo, hiding under a crate for the majority of Hol Horse's assisted assault, demonstrates the extent of Thoth's power by showing its next prediction: that Hol Horse would kick a woman and the woman will be thankful and give him money. Hol Horse is skeptical, but this is proven true when he sees a scorpion crawl up her neck and quickly kicks the scorpion to kill it, after which the results of the prediction follow.

The two then try to follow the next prediction, involving Hol Horse sticking his fingers up Polnareff's nose and the rest of the Joestar group being hit by a truck. Hol Horse, skeptical of the result, but willing to follow through nonetheless, sticks his fingers up Polnareff's nose. A series of events is then triggered that leads up to the Joestar group being hit by a truck.

Boingo now has Hol Horse's full confidence and directs Horse to guide his bullets through series of pipes. However, Hol Horse's watch was off by a few minutes when directed to fire at noon, and the bullets loop around and pierce through the depicted holes in the comic book's pages to hit him instead. Afterwards, Boingo contemplates using his powers to better the lives of others and kicks aside his hiding crate, but the crate accidentally hits Iggy and Boingo becomes assaulted by the dog and becomes even more introverted than before. Thoth then says that, if it was that easy to change their ways, there wouldn't be bad people in the world.

Stone Ocean
He didn't make an appearance in the manga but a comic strip series with a similar look to Thoth is shown.

Trivia

 * Due to Copyright laws, Boingo was renamed "Mondatta", after The Police's album Zenyattà Mondatta in Viz Media's translation.
 * Unlike the main cast's serious battles with rest of the "Egyptian god" stands, their "battles" with Boingo are one-sided on Boingo's part, and they hardly, if ever, notice Boingo's plots against them, "defeating" them only by chance and the mistakes of Boingo's partners.
 * Curious enough, he somehow was able to predict Jotaro's actual death or at least the details of his death (about his head being sliced) several years in the future.