Epimetheus was one of the Titans, son of Iapetus and Clymene. He was the brother of Prometheus, Atlas and Menoetius.
His name is derived from the Greek word meaning 'afterthought', which is the antonym of his brother's name, Prometheus, meaning 'forethought'. In this context, Epimetheus appeared as a foolish character, while Prometheus was the clever one.
Prometheus and Epimetheus were told to distribute characteristics to the newly created animals.
Epimetheus started giving a positive trait to every animal, but lacking foresight, he realised that he had distributed all traits without having any left to give to man. So, Prometheus gave mankind the civilizing arts and fire.
Epimetheus received Pandora as a gift from the gods; a human created by the gods specifically to punish the humans. The marriage of Epimetheus and Pandora is not explicit in any source, but only implied; from their union, Pyrrha, their daughter, was born.
Pandora was given a jar which contained all evils of humanity; curious to see what was inside, she opened it and all evils were released into the world. Shocked, she closed it as soon as she could, but only Hope remained trapped inside.
See Also: Titans, Iapetus, Prometheus, Atlas, Menoetius, Zeus