Tamagotchis, the hungry and needy virtual pets from the 1990s, are back in their original form.

The toys were launched in Japan in 1996 and hatched a worldwide craze from 1997.

For those who are unfamiliar with them, the Tamagotchi eats, sleeps and poops.

It can die, so the "owner" has to take care of it by feeding it, playing games with it and feeding it medicine when it gets sick.

While there have been updates and other iterations of the virtual pet, including a mobile app version, since then, this version is a special release for the toy's 20th anniversary.

The original monochrome, retro graphics are housed in a plastic egg shell that is smaller than the original.

There are six characters for this version.

They are available on Amazon Japan for about 1,400 yen (S$18).

There were also colour-screen versions of the toy launched in the past few years.

Tamagotchi is a portmanteau of the Japanese word for egg (tamago) and the Japanised version of the English "watch".

Those who grew up in the 1990s have a particular fondness for the egg-shaped toys.

There was a shortage of Tamagotchis back in 1997 and lotteries had to be conducted to determine which customers got to buy them.

Some schools banned them and there was a thriving black market for them that even involved the Japanese yakuza.

Tamagotchi from 1997 can still be found for sale online, some for more than S$100.