Grand Cetus

Grand Ketos are Wells and Sophie's Beyblades. The beast inside of it is a whale.

Beyblade: Metal Masters
It was first seen in episode 16, where Sophie used the white version to clear away water so she could view a sunken ship. Later, Wells used the blue version to beat a challenger in three seconds. Gan Gan Galaxy then spied on the "Festival of Warriors"-- a European tournament to select Europe's representatives, when they were discovered. Both of the Ketos were used in the following battle, which they won.

Special Moves

 * Grand Maelstrom(White): Ketos creates A whirlpool that knocks down its opponent.
 * Grand Fleet(Blue): 
 * Grand Deucalion: A combination attack where both Ketos send a tidal wave crashing down on their opponents.

Game
It was released in Wave 5. It is be a Defense Type. There are two variations, Blue and White.

Trivia

 * The one used in the "Aqua Sword Strike" set is a recolored Blue version, or Wells' bey.