In Greek mythology, Mimas was one of the Gigantes, earthborn offspring of Gaia from the blood of castrated Uranus. In the Gigantomachy Apollodorus has Hephaestus kill him with red-hot metal from the forge; Euripides, Apollonius, and Claudian give the death to Zeus's thunderbolt or to Ares/Mars. He was said to lie buried under Prochyte off Naples.
Adapted from Wikipedia, "Mimas (Giant)" · CC BY-SA 4.0
I.Gigantomachy
Like the other Giants, Mimas rose against the Olympians. Apollodorus assigns his death to Hephaestus, who hurls missiles of glowing metal. In Euripides' Ion the Delphic temple sculptures show Zeus burning Mimas to ashes with the thunderbolt. Apollonius of Rhodes and Claudian instead have Ares (Mars) slay him.
Latin poets (Horace, Seneca, Silius Italicus) mention Mimas among the vanquished Giants; Silius places his burial under Prochyte. Claudian hangs Giant spoils in a wood near Etna's summit, naming Mimas among the defeated.
II.Homonyms
The Saturnian moon Mimas and other geographic namesakes are modern or non-mythic. Atlas id mimas-giant is only the Gigantomachy combatant — not to be confused with minor mortal namesakes if any appear in catalogues.