So the Pet Rock was the '70s version of a fake pet, but leave it to the neurotic '90s to create an even more annoying one. The Tamagotchi was invented by Japanese monsters Akihiro Yokoi and Aki Maita and released in the West in 1997. In a cheap plastic shell resided a pixelated cartoon animal. Pressing buttons on the side let you feed, pet and "play with" this critter, which would react accordingly. Take care of it and it would thrive, neglect it and it would starve. You even had to clean up its little digital poop. For some reason, every kid in the world wanted to show some responsibility for once, and over 70 million of the damn things were sold. All of them are dead now.