These are a list of minor characters that have appeared throughout the Dragon Ball Multiverse manga and novelization.
Universe 1
Dabura
Dabura of Universe 1. He is indirectly mentioned by South Supreme Kai of Universe 1. Dabura of this universe seems to still rule over the Demon World.
Vegeta
King Vegeta succeeded his father when he came of age and became the new King Vegeta. Vegeta and the Saiyan people never migrated to other planets nor were they annexed by Freeza. This Vegeta is exactly the same as the Vegeta of Universe 10, but never had the chance to participate in the multiverse tournament like his counterpart.
King Cold
King Cold from Universe 1. In this universe Cold was killed very earlier along with his children Freeza and Coola on Age 712 by the Northern Supreme Kai. The God, after killing his two sons, finished Cold by slicing him in half with his sword.
Freeza
Freeza from Universe 1 was killed as a young child on Age 712 along with his brother and father by the Northern Supreme Kai. It seems that the god killed him by piercing an energy beam through his head, thus killing him instantly.
Coola
Coola from Universe 1. In this universe where Coola was killed very earlier as, it seems, a pre-teenager on Age 712 along with his young brother Freeza and father Cold by the Northern Supreme Kai. The god killed him by piercing an energy wave through Coola's stomach.
Mijorin
Mijorin was a warrior and an original Dragon Ball Multiverse character who fought off an army of evil invaders from his home planet, 7,000 years in the past. In many universes he did it by himself, due to the absence of divine intervention in the affairs of the mortal world. In Universe 1, however, the Supreme Kais considered this evil army a possible threat to the universe itself and helped Mijorin to not only repel the army from his planet, but to destroy it entirely. Southern Supreme Kai came to give assistance to Mijorin and they both destroyed this evil army.
Paragus
Paragus from Universe 1,a universe which all evil was destroyed by the Supreme Kais. He begged Western Supreme Kai to spare his sons life. He was presumably killed by her afterwards.
Bojack
Bojack from Universe 1. Bojack and his gang on this universe were killed earlier on Age 507 before they could have done much damage to the universe by the Southern Supreme Kai on planet Zoltan-4. Even transformed Bojack could not stand much of a chance against the strongest of the supreme gods.
Bido
Bido joined the gang of Bojack after the criminal killed his superior in coupe. After they terrorized the universe for eight years they where destroyed by Southern Supreme Kai on planet Zoltan-4.
Romanesco
Romanesco from Universe 1. Romanesco was the previous Legendary Super Saiyan that was born 1000 years before Broly, he plays a role on Salagir's fanfic "Hanasia, the queen of the Saiyans" which happens 1000 years ago and is canonical to DBM story in many universes he was killed by the combine efforts of many Saiyans, Kibito, Western Kaioshin and of course the first Super Saiyan, the Saiyan Hanasia. However, in universe 1, due to the different events happened 5 million years before when they killed Bibidi, and decided to monitor all threats in the universe Romanesco was killed here by all the Supreme Gods. With their combined energy waves, they threw the mad Saiyan into one of planet Vegeta's Suns killing the monster instantly.
Zangya
Zangya from Universe 1. Zangya was a member of Bojack's gang, she was killed earlier on Age 507 before she and her gang could have done much damage to the universe by the Southern Supreme Kai on planet Zoltan-4.
Universe 2
Crono
Crono is the silent protagonist for the game Chrono Trigger. The character designer for Chrono Trigger was Akira Toriyama, which explains the similar hair and eye shape to Son Gokū. In Dragon Ball Multiverse, Crono hails from Universe 2. He came to the tournament as a spectator.
Son Gokū
Gokū of Universe 2 is not seen, however, it is known that he is the 1/6 brother of Mary Sue. She also carries the child of his son Goten making him one of the grandfathers of her child, along with Vegeta, King Piccolo and King Vegeta.
Gohan
The Gohan of this universe is not seen, however, it is known that he is the nephew of Mary Sue, as she is the daughter of Baddack, Broly and King Vegeta.
She also carries the child of his brother Goten making him one of the uncles of her child, along with Trunks (and technically as King Piccolo's children Piano, Tambourine, Cymbal and Drum can be counted as uncles.)
Dabura
Dabura of Universe 2. While not appearing in the manga or novelization, he is mentioned by his son from the same universe.
Thief
Thief is one of Beelzebub's friends from Universe 2 and has great expertise at stealing things. He came to the Multiverse Tournament only as a spectator.
Hero
Hero is the silent protagonist for the video game Dragon Quest VIII. Akira Toriyama was the art designer for Dragon Quest VIII, and thus designed the character. In the game he is unnamed, so the fanon nickname for the character has become his occupation: Hero. In Dragon Ball Multiverse, Hero appears in the waiting pen of Universe 2 when Arale and Mary Sue are called for battle. He came to the tournament as a spectator.
Jaco
Jaco makes a very brief appearance in the Universe 2 area. After Neko Main "loses" to Gotenks, Jaco suggests to Beelzebub that they leave. He is then seen with the fellow members of Universe 2 leaving for their universe.
Universe 3
Zukini
Zukini is a Saiyan that helped in Freeza's defeat in Universe 3. He was ordered by King Baddack to make a full moon along with several others. His appearance is not specifically shown, but he has been killed since then by Dr. Raichi, participating in the battle against Vegeta (Universe 13), who quickly defeats his ghost along with the rest of his race. His name is a pun of "Zucchini", a vegetable squash.
Hatonek
Hatonek is an elite Saiyan from planet Vegeta. His power level is 12,000 and he has remarkable courage as shown when he went up against King Baddack and said that his plan was for cowards.
His hair remarkably resembles that of base Gohan's from the Cell Games.
Salza
Salza from Universe 3 is the leader of Coola's armored squadron. He is one of the henchmen of World Trade Organization of the Frost Demons Empire. He makes a cameo appearance in a Universe 3 special chapter.
Dore
Dore from Universe 3. He is one of Coola's armored squadron. He makes a cameo appearance in a Universe 3 special chapter.
Neiz
Neiz from Universe 3. He is one of Coola's armored squadron. He makes a cameo appearance in a Universe 3 special chapter.
Universe 5
Unnamed entity
When Zen Buu tried to enter XXI's room, there was an unnamed entity with him. Nothing about him is known.
Universe 6
Mr. Satan
In Universe 6, Mr. Satan's life was identical to that of his Universe 18 counterpart up until Bojack's gang's victory over the Z-Fighters. Mr. Satan, along with the rest of humanity, was reduced to slavery following Bojack's victory.
Emperor Pilaf
Pilaf's life was identical to that of his Universe 18 counterpart up until Bojack's gang's victory over the Z-Fighters. Pilaf, along with the rest of humanity, was reduced to slavery following Bojack's victory.
Universe 8
King Kai
King Kai makes a minor appearance in a Universe 8 special chapter. He warns Gokū about the massacre that occurred on Namek.
Piccolo
Piccolo in Universe 8 remains deceased along with Yamcha, Tien, and Chiaotzu. He asks King Kai what happened on Namek.
Yamcha
In this universe, Yamcha remains deceased and is never resurrected.
Tien
In this universe, Tien remains deceased and is never resurrected.
Chiaotzu
In this universe, Chiaotzu remains deceased and is never resurrected.
Chi-Chi
Chi-Chi makes a cameo in a Universe 8 special chapter, telling the past of Universe 8.
Universe 9
Master Roshi
In the novel, Son Gokū asked Krillin about Roshi, if he was alive and well. Krillin replied he is the same as he always was.
Trunks and Videl's unnamed son
In the novel, it was revealed that Trunks and Videl are in fact married, and have son together. Their son is never seen in DBM.
Universe 13
Baddack
The father of Kakarot and Raditz, he died along with planet Vegeta by Freeza, he made a "debut" on universe 13's poster, alongside King Vegeta, but was not included in the final version.
Universe 16
Android 18
Android 18 is a minor character in the Dragon Ball Multiverse manga. She is seen observing the fight between Bra and Gotenks. Vegetto followed #18's daughter's energy in order to ask #18 about childbirth. After he tracks down #18 and asks her, she answers that everyone should have the right to have children, even herself.
Marron
Marron of Universe 16 is a novelization only character. Her life is identical to her Universe 18 counterpart, until Vegeta and Goku fused via Potara Earrings to create Vegetto. Some times after Vegetto's birth, Vegetto followed Marron's energy to ask her mother about childbirth.
Puar
Puar's life was identical to that of his Universe 18 counterpart up until Gokū and Vegeta used the Potara earrings in order to become Vegetto and defeat Majin Buu. In Universe 16, Vegetto sustained his energy barrier after being seemingly absorbed by Buu and, as a result, did not defuse back into Gokū and Vegeta. Following Buu's defeat, Puar, along with everyone else who had been killed by Buu, was wished back to life. Years later, Puar, along with all the other Z-Fighters, was invited to visit Gohan and Videl to see their newborn daughter Pan.
Universe 18
Baddack
The father of Goku and Raditz, grandfather of Gohan and Goten, and great-grandfather of Pan. He's mentioned by Goku and later by Vegeta (during the Universe's 3 Baddack fight), he died along with the destruction of Planet Vegeta by the hands of Freeza.