Digimon
Digimon, short for "Digital Monsters", is a Japanese media franchise encompassing virtual pet toys, anime, manga, video games, films and a trading card game. The franchise focuses on Digimon creatures, which are monsters living in a "Digital World", a parallel universe that originated from Earth's various communication networks.
Pokémon
Pokémon also known as Pocket Monsters in Japan, is a media franchise managed by The Pokémon Company, a Japanese consortium between Nintendo, Game Freak, and Creatures. The franchise copyright is shared by all three companies, but Nintendo is the sole owner of the trademark.
Tamagotchi
The Tamagotchi is a handheld digital pet, created in Japan by Akihiro Yokoi of Bandai. It was released by Bandai on November 23, 1996 in Japan and May 1, 1997 in the rest of the world, quickly becoming one of the biggest toy fads of the 1990s and early 2000s. As of 2010, over 76 million Tamagotchis had been sold worldwide.