They are called Go Go Hamsters, and if you have a child who wants one for Christmas, you'd better be quick or they'll be Going Going Gone.
The interactive robot pets are proving a surprise hit and are being tipped as the must-have toy of Christmas 2009.
As they cost just £9.99 each and don't need feeding or their cages cleaning out, the AAA battery-powered hamsters may prove an attractive alternative for parents being pestered for a real pet.
Chunk, left, the surf hamster who likes to 'feel the love' and Mr Squiggles, right, the fussy hamster on a mission who hates to be called cute
But they are flying off the shelves, with some stockists boasting that whole shipments are sold out between 30 seconds and three minutes after reaching the shop floor.
In the UK initial demand was so high that Toys R Us did not even list Go Go Pets in its Christmas catalogue to avoid disappointing customers.
A check yesterday found they were 'out of stock' on the websites of Argos, Toys 'R' Us, Tesco, Asda and Hamleys.
On the Toys R Us website parents are restricted to buying two of each item when they finally get a new delivery.
The five animals - Mr Squiggles, Patches, Chunk, Pipsqueak and Num Nums - can explore and interact with a plastic tunnel 'house' and miniature car when set to 'adventure' mode.
Num Nums, left, can detect a carrot from a mile away while 'daredevil' Pipsqueak, right, plays in a plastic bauble
Or simply sit and 'coo' when stroked in your hand with more than 40 different sounds when in 'nurturing' mode.
Their in-built artificial intelligence lets them 'know' where they are in the house, which is sold separately.
They make toilet-flushing or teeth-brushing sounds in the bathroom, or sleeping noises and yawning when they enter their bedroom.
One retailer was yesterday offering four of the hamsters for £120 via online shop Amazon - a mark-up of 200 per cent.
Jerry Storch, chief executive of Toys 'R' Us, said they are a phenomenon on par with the Teenage Mutant Ninja Turtles, the smash hit of the late 1980s and early 1990s.
There are five Go Go Hamsters: Mr Squiggles, Chunk, Pipsqueak, Num Nums and Patches - the last of which is available only as part of a playset.
A clip from the Go Go Pets TV ad which shows the battery-powered animals tearing around plastic tubes and playing in their wheels
Mr Squiggles goes for a drive in his toy car. The toys are set to be this Christmas' must-have present
Real hamsters breed so easily that some owners give them away for free. But when the cost of cages, food and other accessories are added the toys certainly work out cheaper.
UK distributor Character Options has sold 600,000-700,000 Go Go Hamster toys so far in the UK, including play sets and accessory packs, which can cost up to double the price of the hamsters, and extra supplies have had to be ordered from China.
Managing director Jon Diver said: 'The craze has been incredible.
'Children love the movement, magic, personality and emotion of the toys and I think parents love the price point, which you have to consider in the difficult times we are in.'