We may associate them with ancient Egypt's mummified felines and gods — remains from 9,500-year-old burials show that Egyptians kept them close, even to the death — but cats are present in Norse mythology as well. "Freja, the goddess of love, had two cats that pulled her carriage," Jes Martens from the Cultural History Museum in Oslo, Norway told Science Nordic. "And when Thor visited Utgard, he tried to lift the giant, Utgard-Loki's cat. It turned out to be a serpent, the Midgard Serpent, which not even Thor could lift." As well as being a lucky presence, cats could have been useful as mousers on Vikings' long trips at sea.