From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Demons are usually evil beings who enjoy using their powers to generally kill and/or torment those who are weaker than themselves.
 Regular Demons
Demons first appeared in the Dragon Ball: Sleeping Princess in Devil's Castle. They lived in Devil's Castle within the Devil's Hand under the leadership of Lucifer. With the exception of Ghastel, Lucifer's demons used machine guns and bazookas.
Demons later appeared in the filler episode "Goku Goes to Demon Land" as followers of Shula, the "King of the Demon World". Shula managed to open the Demon Realm Gate to the Demon Realm, and kept it open for awhile by wedging his cursed sword in its door, thus allowing many Demons to continually torment the nearby kingdom during nightfall. Contrary to Lucifer's Demons, Shula's followers are martial artists.
The "King of Demons", a supposed Makaioshin, was Dabura, who was first seen being taken under the control of the wizard Babidi. Despite being the king of demons, he was the first to fall to Majin Boo when he was released by Babidi. When he is next encountered, in the Next World, his emotions have changed significantly: he became a kind, very caring creature and helped Bulma Brief, Son Chichi, and Son Videl look for Son Gohan because at the time they all thought he had been killed by Buu even thought he had not.
 Demon Clans
Garlic and his son, Garlic Junior, were introduced in Dragon Ball Z: Dead Zone and leaders of a Demon Clan. Garlic assembled a Demon army after being outclassed by the Nameless Namekian as successor to the then-current Kami of Planet Earth. An enraged Garlic led an attack against the Heavenly Realm in an attempt to take the position by force. The aging Kami, however, sealed Garlic and a majority of his followers in the Dead Zone. Garlic apparently died of old age after being condemned to spend centuries trapped in the void of the Dead Zone, but not before leaving a young son behind to avenge his death by killing the Nameless Namekian (Kami) whom Garlic blamed for his father's demise. A few of Garlic's followers (Ginger, Nicky, and Sansho) survived the battle and raised Garlic. They continued to follow him as their leader until they were killed by the combined efforts of Goku and Piccolo. Later, Garlic formed another group of henchmen named the Spice Boys (Tard, Vinegar, Salt, and Spice), but they were eventually killed by Gohan and Kuririn. The Z Warriors stopped Garlic from killing Kami and taking over the world both times. Unlike Piccolo Daimo's Demon Clan that was composed of Namekians and Mutant Namekians, Garlic and his son were from Planet Makyo. (Makyo means "Devil's Cave" or the "Realm of Demons" in Japanese Buddhism.)
Another Demon Clan led by a Namekian, Slugg, was featured in Dragon Ball Z: Lord Slug. Unlike Piccolo Daimao's Demon Clan that consisted of his offspring, Slugg's Demon Clan was composed of demonic beings whose true origin was not revealed. They have both a hatred and a weakness to sunlight like Lucifer's Demons and the purple-skinned aliens that were followers of Slugg.
 Other Demons
Bojack and his followors were evil, demonic creatures who also enjoyed torturing those weaker than themselves throughout the universe until they were sealed away by the four Kaios. As a result of North Kaio's death after Cell exploded on North Kaio's World, Bojack made his way to Planet Earth with his minions only to ultimately be killed by Son Gohan in his Super Saiyan 2 form to end Bojack's reign of terror.
The Majin were a race of magic-created Demons. The most famous Majin was Majin Boo who was created by Bibidi. They are not be confused with people under the control of Babidi's magic who are also called "Majins". In the films, two other magic-created Demons appeared, Janemba in Dragon Ball Z: Fusion Reborn and Hirudegarn in Dragon Ball Z: Wrath of the Dragon. Ozotto, who appeared in Dragon Ball Z: V.R.V.S., was also a Majin.
 List of Demons
 Regular Demons
- Dabura – King until being taken by Babidi. Is later killed by Fat Boo in 774 Age. As the "King of Demons", he may be a Makaioshin.
- Shula – Appears in "Goku Goes to Demon Land". As the "King of the Demon World", he may be a Makaioshin.
- Melee – Appears in "Goku Goes to Demon Land".
- Gola – Appears in "Goku Goes to Demon Land".
- Lucifer – Appears in Sleeping Princess in Devil's Castle. He is a Makaioshin according to Dragon Ball: Daizenshū 7.
- Ghastel – Appears in Sleeping Princess in Devil's Castle.
 Piccolo Daimao's Demon Clan
- Piccolo Daimao (Leader)
- Piano, Tambourine, Cymbal, Drum, and all the other unnamed Mutant Namekians
- Piccolo Junior
 Garlic Jr.'s Demon Clan
- Garlic (Leader)
- Garlic Junior (Leader)
- Ginger, Nicky, and Sansho
- Spice Boys (Spice, Vinegar, Salt, Mustard)
 Slugg's Demon Clan
 Magical beings
- Ozotto - Demon fought before the Cell Games.
- Majin Boo – Created by Bibidi.
- Janemba – Created from pure evil.
- Hirudegarn – Created by the Kashvar.