Peleus scaling

Afterwards he married Thetis, daughter of Nereus, for whose hand Zeus and Poseidon had been rivals; but when Themis prophesied that the son born of Thetis would be mightier than his father, they withdrew. But some say that when Zeus was bent on gratifying his passion for her, Prometheus declared that the son borne to him by her would be lord of heaven; and others affirm that Thetis would not consort with Zeus because she had been brought up by Hera, and that Zeus in anger would marry her to a mortal. Chiron, therefore, having advised Peleus to seize her and hold her fast in spite of her shape-shifting, he watched his chance and carried her off, and though she turned, now into fire, now into water, and now into a beast, he did not let her go till he saw that she had resumed her former shape.

Author: Apollodorus
Source: Library