The Tamagotchi is a handheld virtual pet game created by Aki Maita. The name is a portmanteau of the phrase "Tamaogo tchi" (たまごっち) meaning "lovable egg" in Japanese.
Tamagotchis were introduced in 1996 and were a huge fad for some time, with millions sold.
Tamagotchi pets were small, plastic eggs containing a tiny computer with a simple black and white LED screen. Below the screen were three buttons. The egg was attached to a keychain, to encourage owners to always keep the pet close by.
Caring for the pet was fairly simple. A tiny creature would appear on screen after the egg was turned on. By pressing the three buttons, the owner could feed, bathe, discipline, or amuse the pet.
If these four actions were done in moderation and at a fairly regular pace, the creature would eventually evolve into a better animal. If the creature was poorly cared for, it would either die* or evolve a sickly weak animal.
The game ends after the creature reaches its ultimate state of evolution, and "returns to its own planet." This usually takes several days.
There were many Tamagotchi spin offs, with different animal types, including "Forest Tamagotchi" and "Angel Tamagotchi."