Symbolism of evil
Cats looked mysterious creatures for humans, especially black ones, so they became the symbol of bad luck or the forces of darkness and even were associated with magic in Western tradition. No wonder that the black cat is one of the symbols of the Halloween.
In Kabbalah as in Bouddhism the cat is associated with the serpent: it represents the sin, sometimes depicted at the feet of Christ.
In Celtic tradition the symbolism of the Cat is not favorable as well. It is the guardian of the Underworld. Black cats were seen as evil and were sacrificed.
In numerous traditions the Cat, especially the black one, symbolizes darkness and death.
Symbolism of goodness
The lunar goddess Bastet having the form of Divine cat was worshiped in Ancient Egypt. She was the protector oh humans. She kills the serpent Apophis, the Dragon of Darkness which represents the enemies of the Sun. The cat symbolizes here the force and the ability to help people to gain victory over their hidden enemies. Cats even were mummified.
In Ancient Rome the cat was sacred to Diana, the Moon goddess, and was considered as the guardian of homes.
In Muslim religion the cat is also seen rather favorably unless it is black. It is honored for saving Mohammad from the serpent.
It is often said that the cat has seven lives.