The Twelve Generals

The Twelve Generals are leaders of the Moon Bear King's forces and based on the twelve animals of the Chinese Zodiac. They are also on the search for the Thief of Calibrus, Kutaro, on the tyrant's orders. Each general has a unique personality and not all of them are completely loyal to the Moon Bear King, with some following him more for their own personal gain.

Castle Grizzlestein
General Tiger Duties: guard the Black Castle, the Tyrant and follow his orders, which later includes making sure Kutaro doesn't get out with the Knight's Shield, and/or rescue the Sun Princess Pikarina, and finding and destroying Kutaro.

Moonwood
General Rat

Duties: Corrupt the entire Moonwood, and defeat Kutaro.

General Snake

Duties: Produce useful toxins, Destroy Kutaro (and the Moonwood if necessary).

Moonshine Sea
General Pig

General Sheep

Duties: pollute the Moonshine Sea with magic oil, and capture or destroy Kutaro.

Wild Waste
General Bull

General Horse

Duties: Pollute the Wild Waste, and destroy Kutaro.

Hallowee Ville
General Monkey

Duties: Build vital assets to assist the Tyrant's rule, control the Ville, spy on Kutaro, steal his collected moonstones pieces, assist in the Moon Clock plot, keep his moonstone piece away from Kutaro (if only to stall for time if necessary), and destroy Kutaro.

General Dog

General Robo Dog

Duties: assist General Monkey, destroy Kutaro.

Land of Time
General Rabbit

General Rooster

Duties: Conquer the Land of Time, find Mr. Pink to complete the Moon Clock plot, destroy Kutaro.

General Dragon

Duties: Collect the souls of Earth's children for the Moon Bear King, destroy Kutaro.

Trivia

 * Although the game was advertised to have 13 major boss fights, (The twelve generals and the Moon Bear King). General Pig and Sheep are fought as one boss, meaning that there are only Twelve, though Robo-dog may count as a Major Boss.
 * The fights with some of the Generals seem to resemble each other in pairs. Tiger-Dog, Snake-Dragon, Horse-Rabbit, Rat-Rooster.
 * Despite the size, powers, or successes of some Generals like General Dragon, Snake, or Monkey, its mention that if General Bull and Horse weren't fighting each other and would work together they would be the most powerful and successful pair of all the Moon Bear King's Generals.
 * Despite them being dead, their child selves must most likely had survived and revived, and became good again like Little Bear. And it might possibly be after Kutaro went back home in Japan, the Moonstones being put together, or both.