Which Spartan survivor of Thermopylae later fought and died at Plataea?

The Spartan survivor of Thermopylae who later fought and died at Plataea was Aristodemus.

Aristodemus was one of the 300 Spartans sent with King Leonidas to Thermopylae in 480 BC. He and fellow soldier Eurytus suffered an eye illness and were ordered to return home before the final Persian assault. Eurytus went back despite his blindness and died in the battle, while Aristodemus returned to Sparta alive.

Because he had not shared the final stand, the Spartans branded Aristodemus a coward. Herodotus says he was denied ordinary social courtesies and called “Aristodemus the Coward.” Another Spartan survivor, Pantites, had been away on a mission and later took his own life after returning in disgrace, so he is sometimes confused with Aristodemus.

At Plataea in 479 BC, Aristodemus fought with exceptional, almost reckless courage and was killed. Sparta accepted that he had redeemed his reputation, although it awarded him no special honor because his conduct was considered too suicidal rather than disciplined.