This piece can be used as a decorative rook in normal or "queen's" chess, as well as can he used as a "Sea Monster" in the ancient and exotic games of Perfect Chess, Tamerlane/Timur Chess, as well as Complete Perfect Chess or Full Chess. http://history.chess.free.fr/tamerlane-full.htm
"During the reign of Timur Lenk, also called Tamerlane (1336 - 1405), this game was played often in Persia. Some old sources tell that Timur invented the game himself, but this attribution is, as more of such attributions, not necessarily true. The game is a large variant of Shatranj, the orthodox chess-game of that period. As a consequence, the game was also called Shatranj Kamil (perfect chess) or Shatranj Al-Kabir (large chess).
The game was mentioned in Murray's History of Chess, and discussed in more detail, with sample game, in the book of Gollon." - http://www.chessvariants.org/historic.dir/tamerlane.html