Hattifatteners’ Island

Once a year, during a thunderstorm, the Hattifatteners meet in large numbers at the deserted Hattifattener’s Island. They become charged up with electricity and start glowing, rocking back and forth, and gather around a blue pole with a barometer attached to it.

In Tales from Moominvalley, Moominpappa travels with the Hattifatteners to the island. He then realises that the only thing that enliven the normally quiet, expressionless Hattifatteners is a great thunderstorm.