The African Moon Moth, Argema mimosae, is a large silk moth in the family Saturniidae and can be found widely in Eastern and Southern Africa, including near the east coast of South Africa.
An adult has a wingspan of 10 to 12 centimetres (3.9 to 4.7 in) and is 12 to 14 centimetres (4.7 to 5.5 in) from head to toe, as it were. However, what appears to be an elongated tail is in fact a second pair of wings. Its forward wings have a distinctive grey-coloured furry edge.
It is basically emerald green with yellow and red eyespots on its wings. This one, which I encountered at the Butterfly Park in Benelmádena, is, I believe, a female.