A failed fusion can only occur when fusing using the Fusion Dance in an incorrect way. Many of the fusions in the series have been performed incorrectly, leading to a failed fusion. There are examples of failed fusions from Dragon Ball Z, from movies, and from video games. Goten and Trunks achieve this form when the Fusion Dance goes wrong, probably because Trunks stretches his finger at the moment he and Goten say, "-sion!". The result is a fat version of Gotenks. He tries to run but tires very quickly. For a moment, Krillin and Yamcha think that the fusion has succeeded and that Gotenks has to be fat to regulate his power, similarly to Majin Buu. However, they soon change their minds when they see that fat Gotenks becomes winded after a brief and slow run. Fat Gotenks is also seen in Dragon Ball: The Return of Son Goku and Friends! Goten and Trunks as Fat Gotenks say that they did not practice the fusion dance for a long time, and then they defuse. He is a playable character in Dragon Ball Heroes, but in other video games, he can not do any special attacks and is already tired after a few kicks and punches. In the case of Dragon Ball Z: Buu's Fury, neither he nor the skinny variant can even move, and defuse automatically after a few seconds so that a successful fusion can be performed. Goten and Trunks achieve this form of Gotenks when the Fusion Dance goes wrong for a second time. The failure is due to a lack of coordination, as when Goten and Trunks say "HAAH," their fingers do not meet.
Skinny Gotenks can barely stand on his feet without getting tired, and he coughs a lot as well. Goku and Vegeta fusing into Gogeta. He is a fat and embarrassingly weak fusion fighter, named by South Kai in Dragon Ball Z: Fusion Reborn from Vegeta and Goku. In this form, Veku is nowhere near as strong as he would like to be, and his ki and stamina are extremely limited. He does not perform any special ki attacks due to these limitations, as well as being unable to punch or kick well due to his fat body. Instead, all he is capable of doing is pass gas and escape battle with his surprisingly fast Rabbit Feet Technique. Like most fusions, there is a 30-minute time limit before he defuses back into Goku and Vegeta. Veku first appears in Fusion Reborn, in Goku and Vegeta's attempt to beat Super Janemba. King Kai blames Vegeta for the blunder, claiming that Vegeta didn't extend his index finger, which led to the fusion failure.
On their third try, Goku and Vegeta manage to successfully form Gogeta and leave to confront Broly.
Luckily, Veku is able to take Janemba's blows and outmaneuver him until the 30 minutes of fusion are finished, allowing Goku and Vegeta a successful opportunity to re-fuse, this time successfully into the deadly Gogeta, who easily eradicates Janemba. In Dragon Ball Super: Broly, Goku and Vegeta fail twice to properly perform the Fusion Dance, resulting in failed fusion Gogeta making two appearances: as Veku, firstly due to Goku's finger slipping below Vegeta's and the second time as an extremely skinny Veku due to Goku is being tilted at a 45-degree angle while Vegeta is tilted at a 60-degree angle. On their third try, Goku and Vegeta manage to successfully form Gogeta and leave to confront Broly. Before Broly, concept arts for a skinny Gogeta were originally shown in Daizenshuu 6, in the Fusion Reborn area, but the character was not included in the final version of the movie. A skinny Gogeta card exists in Dragon Ball Carddass.
Kamehameha - Veku can use this in Dragon Ball Heroes and Dokkan Battle.
Skinny Gogeta is also in Dragon Ball Z: Buu's Fury, appearing when the player fails to do a proper fusion. Veku is a playable character in Dragon Ball Heroes, Dragon Ball Z: Budokai 3, Dragon Ball Z: Dokkan Battle, and Super Dragon Ball Heroes: World Mission. In Dragon Ball Xenoverse 2, he appears as one of five chibi avatars that can hover around the Future Warrior and comes in his base, Super Saiyan and Super Saiyan Blue forms. Kamehameha - Veku can use this in Dragon Ball Heroes and Dokkan Battle. Rabbit Feet Technique - A running away technique used by Veku to flee from Super Janemba. This form of Tiencha arrives in Dragon Ball Z: Budokai 2, when Yamcha and Tien Shinhan stretch their hands when they say "HAAH" in the last stage of the Fusion Dance, a costly mistake. In this form, Tiencha can still fly but can't do any special attacks. He can only use punches, kicks, and simple ki attacks, and even these cost him a large portion of his energy. After a combo attack, he coughs, and if he tries a special attack like the Dodohameha, he again coughs, causing the attack to fail.
Scott Shelly ( Hangul:셸리 ) is one of the female protagonists in the webtoon. She begins a one-sided relationship with Jay at the start of the series but as the story progress they have a mutual crush on each other and as of chapter 378 they are in a relationship. Shelly is the only female member of the Humming Bird Crew. Because she stayed at England before coming to Korea her personality is perceived as very headstrong. She does not like it when people talk badly about her friends, especially Jay. Shelly also has a lot of stamina and strength, she can keep up with the group's pace when racing and can actually send people flying with her punch (Although that may be for comedic reasons) but never got into the street fights with the guys of the crew. When she was hit on in her first appearance on the series she refused with a lot of sass. Mia described her as someone who can confidently express her thoughts and feelings. Although her words are harsh, it is because she never sugar coated her words with her friends. And with Jay, Shelly is very clingy and flirtatious. She has very foreign features: pale skin, her eyes actually look more mint green in color than blue, blond wavy hair. It is known later in the series that she has a tattoo in the side of her arm near the wrist that reads out "temet nosce" or "Know Thyself". At school she wears her uniform usually without the red vest and both wears the skirt and pants.
She refused on taking him to the hospital but Jay refused.
She is often seen wearing high-end brand clothing, but also occasionally wearing street wear and tomboyish clothes. When riding her bike, she usually wears a jacket and helmet with the same color as her eyes or the Hummingbird crew's hood. She is tall, with long thin legs, a small waist and a bigger bust. Not much is known about Shelly, but it is established that she is from England and she requested to transfer to Sunny High School because of Jay. It was told in an early episode (Ep. 27) that she will be in Korea for one semester. Shelly is the granddaughter of Sunny High School's principal, Nick. When Shelly was a kid, she didn't want to get married and promised Nick that she will just live with him forever, which caused Nick to think that Shelly is not interested to guys until she got interested in Jay. That also caused the over protectiveness of her grandfather. Jay saw what happened and chased the thieves to get her purse back. She refused on taking him to the hospital but Jay refused. She picked up his student ID that had fallen to the ground and, motivated by her encounter with Jay, called her grandfather, asking him to let her attend Sunny High School. Her second meeting with Jay was in their classroom. She kissed him out of the blue and the gossip that Shelly and Jay were in a relationship quickly spread around the school.
When Jay was about to say sorry, he got a pink rose from Minu, saying that he should give it to her.
When Jay, Dom and Minu got suspended, Shelly visited them and scolded Dom and Minu badly about how Jay got caught with their actions. Jay got pissed and told her to screw off, she ended up crying and running away. When Jay was about to say sorry, he got a pink rose from Minu, saying that he should give it to her. He couldn't and Shelly went on saying that she'll forgive him if he became her boyfriend for a week and Jay agreed. She joined Hummingbird as the only female on the team, she continued to flirt with Jay and when Jay was teaching Mia how to ride a bike, she kept on intervening and wanting him to teach her even though she knows how. On a special episode, Shelly was seen riding a bike in Jay's neighborhood. Minu and Kay noticed her, Kay was thinking of who might Shelly go out with and ended up being shocked that it was his brother. In the last scene, Jay and Shelly are resting after riding their bike together, and she comments that Jay suits biking more than studying. The Preliminaries for the League of Street has started, only Dom and Jay were able to race at the first two rounds. After that, they found out that Jay's birthday was near and planned to celebrate it. She didn't showed up at school on his birthday because she was the one who prepared the gift that they got for him.
When the boys with the worried June except Jay planned to give Jay a strong alcoholic drink, they didn't expect Shelly to drink it, thinking it was juice. They are dumb-founded and later on, a drunk Shelly came closer to Jay and told her how she was hurt by his actions and proceeding to kiss him the second time. They pulled Shelly of Jay who was already littered with kiss marks. Mia was the one who brought Shelly home, when she was sober enough, Mia asked her if she liked Jay which she answered yes. Mia told her how she envied her for being able to confidently express her thoughts and feelings. Shelly answered that she doesn't understand Mia's concern and told her an advice to start believing in herself more and learning to love herself. This pushed Mia to contact the modeling agency that reached out to her. Before the race, Shelly was being hit on by a member of the Bullet Crew who will be racing against them. The glasses guy kept on hitting on her even when she's denying him. Vinny came to her rescue and punched the guy when he didn't stop.