Parents hoping to buy their children Go Go Pets for Christmas face disappointment because the American “interactive hamster” toy is so popular that demand has far outstripped supply. Character Group, the British distributor, said that media attention had pushed sales to an “unbelievable level” and that it would be out of stock until further notice. Go Go Pets, which squeak and scuttle along the floor, are available online, with some private sellers hoping to cash in on the scarcity of stock by offering the £9.99 toy for more than £30.