Today I came across a pun in Herodotus' Histories.
Midas dedicated the royal throne from which he pronounced judgments while sitting in state, and it is well worth seeing. This throne is in the same place as Gyges' bowls. The Delphians nicknamed the gold and silver which Gyges dedicated "gygantic," after its donor.
So Herodotus demonstrates the art of early Greek punnery. As the origin of the word gigantic is unknown (from Greek gigantikos "of the giants," ultimately of an unknown source). This just adds to the mystery of the ancient languages that influenced Greek.