Western Astrology: Astrological Compatibility Cancer: Cancer the crab is the fourth sign in the zodiac. The Moon is the ruling planet of this cardinal water sign. A person born under this sign will be both protective and complex. Gemini signs are the most imprecise of all, with most holders possessing a secretive and subtle nature. Emotionally, they are very much like a crab themselves with their tough exterior persona and soft interior. Cancers can be quite sensitive and love to stay home. Cancers like to collect objects like stamps, coins, or souvenirs. They often prefer to live near or on the water, particular the ocean. more about Cancer Now please select your partner’s astrological sign: