This article is from the Final-Fantasy and other Square Soft Games FAQ, by email@example.com (Nick Zitzmann) with numerous contributions by others.
All the dances are learned in self-explanatory places (caves, deserts,
etc.) except for this dance.
There are only two places in the game where Mog can learn this dance -
the Lete River and the Serpent Trench. Both places are only accessible
in the World of Balance, so if you reach the World of Ruin and don't
know this dance, you'll never be able to learn it.