First released in 2002, TOMY MicroPets had a pretty great run in the states. They stand a little under two inches tall and made it into the Guiness Book of World Records for being the smallest sound-activated self-powered toy at the Tokyo Toy Fair that same year.
• Wake up your MicroPet by pressing the button on it's head.
• Talk to your MicroPet to make it react.
• If you repeat the same command over and over, it'll ignore you.
• Hold down the button on it's head for three seconds to make it sing a lullaby and go to sleep.