According to Indian mythology, the world rests on the head of a great elephant, and when, for the sake of rest, the huge monster refreshes itself by moving its head, an earthquake is produced. The elephant is called “Muha-pudma.”
“Having penetrated to the south, they saw the great elephant `Muha-pudma,' equal to a huge mountain, sustaining the earth with its head.” —The Ramayuna (section xxxiii.).
The Lamas say that the earth is placed on the back of a gigantic frog, and when the frog stretches its limbs or moves its head, it shakes the earth. Other Eastern mythologists place the earth on the back of a tortoise.
Greek and Roman mythologists ascribe earthquakes to the restlessness of the giants which Jupiter buried under high mountains. Thus Virgil (Æneid, iii. 578) ascribes the eruption of Etna to the giant Enceladus.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894