The anime known as Cowboy Bebop is easily one of the finest works of art produced in the genre — in fact, it has influenced other groundbreaking shows, such as, Firefly, released four years later. Set in a field of cyberpunk extravagance, the series deals with concepts ranging from existentialism to space eco-terrorism.
Its popularity is great enough that Netflix has already begun preparing a live-action version (tentatively out in 2021.) The characters in Cowboy Bebop, main or otherwise, are complex enough to warrant full-scale psychological analyses of their behavior. In lieu of scientific jargon, however, here they are assigned to the most suitable sign of the Chinese Zodiac.
12 Rat - Faye Valentine
Faye is a loner, but she tries her best to rationalize her loneliness as solitude. She has trained herself to survive the toughest of situations, quite like a Rat would, considering she "owes" money for medical services that kept her alive (without her knowledge or permission.)
Faye pretends to put on airs around the Bebop, masking her genuinely compassionate nature with elitism. This is largely because she is unable to trust or create bonds with anyone anymore, though this begins to change slowly.
11 Ox - Jet Black
Where Spike is the wayward child with an unquestionable talent for firearms, Jet is the gruff father figure who takes care of everything (receiving minimal help from the others.) He is slow to action, like the classic Ox, but when he has his mind set on something, it usually ends up accomplished.
Jet occasionally seems like a tyrant, especially when he insists on things being done a certain way, but this is only because he prefers being the responsible, organized one — the only person standing between a working ship and heap of junk.
10 Tiger - Spike Spiegel
The hero, and simultaneously antihero, of the story is Spike Spiegel. He is independent to a fault, making him rather unruly and hard to control in terms of his actions. Spike usually plays the game his own way, even if it leads to mass destruction and loss of profit (because at least he could squeeze some of that adventure in.)
Although he rarely shows it, he is a kind man in his own way, accepting three new crew-members regardless of his perennial complaints about kids, animals and "loose" women.
9 Rabbit - Ed
Ed is impossible to discipline, causing a lot of problems for the orphanage she checks herself into. She is almost like a wild animal, perfectly embodying the Rabbit; for example, she sometimes walks on all fours and growls at people to show anger.
At the same time, Ed is the single most intelligent entity in the show, perhaps even the Solar System, which makes it that much more difficult to manage her behavior. In literally zero cases does she listen to anyone about anything, given that her intuitions tend to be far more accurate.
8 Dragon - Red Dragon Crime Syndicate
Ironic, but appropriate. This underground organization is a sort of Cyberpunk Yakuza, controlling a variety of illicit activities from drug smuggling to assassinations. As a Dragon, the Syndicate wields a considerable amount of influence on both economy and government, but also expects absolute obedience and servitude from its members.
In fact, the penalty for defection is death, as Spike discovers when he plans to elope with Julia. The Syndicate only becomes more destructive when Vicious' coup takes effect.
7 Snake - Vicious
The slimiest character, Spike's dark half, his archenemy, is Vicious. His covert modes of action combined with his malevolent urge to sit on the throne make him a terrifying opponent (his Syndicate superiors are scared of him.)
Vicious never exposes his thoughts to anyone, preferring to concoct his vile plans away from prying eyes — not that it matters because he openly stakes claim on the Syndicate by the end of the series. His vengefulness is rather evident from his vendetta against Spike, trying for years to kill his ex-partner.
6 Horse - V. T.
The Horse is a dynamic force, every person born under it are blessed with the ability to deal with the most impossible of tasks with great confidence.
Victoria Terpsichore is one of these people: her attempt to rescue Bebop goes against everything she feels about Spike's job, but her honor and sense of justice demand she does it anyway. In another case, she goes to the aid of a waitress named Muriel as she is being harassed by aggressive bounty hunters.
5 Goat - Julia
Julia meets Spike through his work (he lies unconscious outside her house, having been gravely injured.) Being a Goat, Julia cannot see a person suffering, and helps him recover, while hiding out at her place.
She finds it tricky to pick between the people she cares about, as in Spike and Vicious, especially when the one of them demands that she murder the other. Julia has displayed a few unfavorable Goat characteristics: in her impetuousness, like when she runs away instead of telling Spike about Vicious' intentions.
4 Monkey - Ein
Ein is first introduced in the episode, Stray Dog Strut, a "data-dog" worth a massive fortune. Quite contrary to a dog, Ein acts more like a Monkey given his hyperactive curiosity.
He is extremely enterprising, regularly more so than the Bebop's crew, shown through his quick-wittedness and problem-solving skills. For instance, Ein takes both Spike and Abdul Hakim on a wild goose chase through the streets, ending with the two men soaking wet in the canal.
3 Rooster - Grencia Mars
Grencia Mars is the definitive Rooster: he is polite and friendly, striking up amicable conversations with near strangers, including Vicious and Faye. Having fought in the War of Titan, he is obviously courageous, refusing the immoral choice even if the alternative is much worse.
Grencia is a symbol of pity, unfairly targeted by the government, imprisoned, and forced to consume experimental medication that results in breast development — and somehow, he still retains his sense of dignity.
2 Dog - Anastasia
Anastasia, known to Spike as Annie, used a small corner shop on Mars before her murder by the Syndicate. This raises doubts about her association with the underworld, but her loyalty to Spike indicates that she is a typical Dog.
For instance, she feeds him a truckload of ammo to help in the upcoming fight against Vicious. Syndicate goons soon ransack her shop, shooting her when she plainly refuses to reveal where either Julia or Spike have gone.
1 Pig - Laughing Bull
Laughing Bull is Spike's guru, whatever that implies in a space-faring cyberpunk universe. As a Pig, he has achieved a mental state that is almost never perturbed, irrespective of what he experiences.
As such, he provides emotional support to those who meet with him, often in the form of inscrutable prophecies. The Pig is best known for simply observing life as it goes by, and Laughing Bull might well be the poster boy for this sign.