Japanese mythology, this three legged raven called 八咫烏(Yatagarasu) .咫(ta) means about 18cm, but
八咫(yata, 八 is eight in japanese) does not mean that 144cm. It means very very big raven.
Yatagarasu has three legs. The first leg means that Japanese God or 高天原(Takamagahara), second leg is Earth , third is humans.
wikipedia : ja.wikipedia.org/wiki/%E5%85%A…
(This is japanese page )