Eggs (卵, Tamago) are a common food and one of the most versatile ingredients used in cooking as well as hatching. They are important in many branches of the modern food industry.
King Piccolo Saga
Namekians breed asexually by spitting eggs out from their mouths. King Piccolo was the only Namekian seen to make these eggs on screen, but Grand Elder Guru is known to have given birth to more than hundred Namekians like this.
One notable Namekian egg was the one King Piccolo made as he died, which spawned his son/reincarnate, Piccolo Jr.
Piccolo Jr. Saga
At the end of the Piccolo Jr. Saga, Goku and Chi-Chi meet an Old Scientist who, at some point during his researches, found the last egg of the Hikui Bird species inside Mount Kiwi's volcano. After Goku defeats the Pilaf Gang who attacked them inside the volcano, he, Chi-Chi, and the scientist assist to the egg's hatching. Chi-Chi takes one of the egg's pieces, and Goku later uses it to repair the holes at the bottom of the Furnace of Eight Divisions that caused fire to emerge from underground and consume Ox-King's castle on Fire Mountain.
Imperfect Cell Saga
When Cell was first awakened in his timeline, both Android 17 and Android 18 were not present, having already been taken out by Future Trunks. So he kills Future Trunks and steals his Time Machine in order to complete his evolution, going back in time to the date set by Future Trunks when both Androids were still functional. In order to fit into the machine, Cell had to revert back to an egg. After getting to the past he hatches. The pieces of the egg were later found by Bulma.
When Bulma gets a phone call from someone stating that they found a strange machine with the Capsule Corporation company logo near Gingertown, Bulma, Gohan, and Future Trunks set out to find it. They find a beat up machine that turns out to be a Time Machine and Cell's egg inside the Time Machine.
Majin Buu Saga
In the movie Dragon Ball Z: Battle of Gods, the God of Destruction Bills reduces an egg to ashes with only one finger using his special powers when Whis shows him the past battle between Goku and Frieza on Namek.
The Gatchans, characters from Dr. Slump who make appearances in Dragon Ball and in the movie Dragon Ball: Mystical Adventure, hatched from an egg brought home by Senbei Norimaki from a time traveling trip.
In Kajika, Dragon Eggs are extremely rare. The dragons of Ronron Island were thought to be extinct when a great storm killed the last two adults, but later, one egg was found and kept in the island's research institute. It was soon stolen by the gang leader and billionaire Gibachi because, according to legend, if one drinks the blood of a young dragon, they will gain tremendous power. This is because baby dragons have dragomin in their blood, which allows them to mature extremely fast. A girl named Haya retrieves the egg from Gibachi and goes on a quest to return it to the island. The main protagonist Kajika meets the girl and saves her from Gibachi's men. Haya then asks Kajika to help her on her quest. When the egg hatches, Gibachi and his men wound the young dragon, and Gibachi drinks its blood, which turns him into a powerful dragon-man.
Video game appearances
A side mission in Dragon Ball Z: The Legacy of Goku requires finding a mother pterodactyl's egg. In Dragon Ball Z: The Legacy of Goku II, the Z Fighters have to move a mother brontosaurus' eggs in order to destroy one of the generators of the barrier protecting Dr. Gero's Laboratory in the Northern Mountains.
Bio-Androids still in their egg are enemies in the computer game Dragon Ball Online.