1 Minnesota Jones: Hippodamus tells a story about the centaur Pholus, who like Chiron was not bestial as other centaurs, but wise.
2 Minnesota Jones: Rather than cavort in forests, he lived in a cave on Mount Pelion, a rustic farming life, and was a friend to Heracles.
3 Minnesota Jones: After Heracles was wounded slaying the Lernaean Hydra, he requested to be taken to Pholus, on a stretcher with wheels.
4 Monty: You mean...
4 Minnesota Jones: He took a gurney to the centaur of the Earth.

Pholus was indeed a centaur in Greek myth, who is said to have lived in a cave on (or at least near) Mount Pelion, which overlooks the modern city of Volos. Although Wikipedia says nothing about where the name of Volos comes from, the resemblance to Pholus is interesting.

Ah... but Wiktionary says of the etymology: Uncertain. Possibly from Byzantine Greek Γόλος (Gólos), from Turkish Yolkaz, from Ancient Greek Ἰωλκός (Iōlkós). The change in consonants stems from a 19th century attempt by learned scholars to link the name with the Ancient Greek term βόλος (bólos, “fishing net”) or βῶλος (bôlos, “lump of soil”).

A likely story.

Anyway. Pholus was indeed a friend of Heracles, who slew the Lernaean Hydra as the second of his famous Twelve Labours.

The rest of the mythology in this comic may be slightly embellished.

On an unrelated note, Jules Verne's Journey to the Centre of the Earth was my favourite book for a long time as a child, and I read it many times over.