Doctor Who is known for the changing of its main character every few years, and with each regeneration, the Doctor gets a complete overhaul - from preferred clothing style to core personality. Though the Doctor retains the memories and knowledge of previous incarnations, they share little else, as a complete shift in persona takes place.
Many of the Doctor's personalities have specific characteristics and traits that line up perfectly with a zodiac sign. People have been reading the stars since the dawn of time, and as a man among the stars, the Doctor should be no exception.
Aries - The Second Doctor
Patrick Troughton's Second Doctor wasn't afraid to do difficult things for the greater good, but he certainly had fun while doing it. He believed in courage as a virtue, though his actions often bordered on recklessness. The Second Doctor did not care much for leading, but he cared less to have others do it, an Aries to his core.
Aries tend to be brazen, unafraid of conflict, and courageous with a grand sense of adventure. They are bold, have little to no filter, and can be impulsive in the heat of the moment, preferring to follow their own rules than that of an authority figure.
Taurus - The Third Doctor
Jon Pertwee's Third Doctor was a tinkerer, a lover of science and gadgetry who wasn't afraid of a fight. Like most Tauruses, he didn't have a lot of patience, and would often seek to gain control of whatever situation he was facing.
Tauruses tend to be more grounded in the world around them, and prefer to be in control. They can be stubborn but remain stable in chaotic situations. The Taurus is always the dependable person in the room.
Gemini - The Eleventh Doctor
Matt Smith's Eleventh Doctor was one of the best to date. Energetic, spontaneous, and like most Gemini, often a big kid at heart. He is relentless in his pursuit of adventure across the universe, constantly on the lookout for a new puzzle to solve, all the while chatting animatedly to anyone who would listen.
Gemini are erratic, curious, and playful. They use humor as an emotional crutch, yet will argue as a form of flirtation. A Gemini will talk to just about anyone or anything and has an endless curiosity, always seeking answers to new questions.
Cancer - The Fourth Doctor
Tom Baker's Fourth Doctor often seemed callous, true to being a Cancer, he had a tougher exterior than his previous incarnations. Rather than expose emotion, he parted ways with his companions with nary a word, though he missed them when they were gone.
Cancers are intuitive with contradictory mood swings that often make them seem brusque or uncaring. They set firm boundaries, hide any sense of vulnerability, and will forgive almost any transgression, but will never forget.
Leo - The Tenth Doctor
David Tennant's Tenth Doctor was frequently larger than life, giving fans one of the best seasons of the show yet. He was ionate in his relationship with Rose, but largely self-centered while traveling with Martha. Like his fellow Leos, the Tenth Doctor struggled mightily to overcome the heartache of losing both romantic and platonic companions.
Dramatic Leos stand out in a crowd, tend to be a bit vain, and have exuberant personalities that draw people to them in any situation. Their ion often means that they are ruled by their heart, and any hurt they feel can easily be seen by anyone around them.
Virgo - The Twelfth Doctor
Peter Capaldi's Twelfth Doctor was the ultimate Virgo, giving everything he had to every task put before him, no matter the cost. He had little restraint in ing judgment on those he encountered, though he rarely seemed to realize he was doing it at the time.
Virgos are practical, fiercely loyal, and consummate perfectionists. They can be judgmental, though they mean well by it. Virgos are usually bursting with ideas, and always have a quick fix for any issue they come across.
Libra - The Fifth Doctor
Peter Davison's Fifth Doctor didn't care much for confrontation and would do his best to resolve situations using reason rather than action, a very Libra approach indeed. He would often go so far as to toss a coin rather than make a choice and spent much of his time reacting to conflict, rather than seeking it out.
Libras have a preference for symmetry in most things and prefer to avoid making decisions. They dislike being alone and will go out of their way to avoid conflict, which pairs well with their ability to see both sides of most situations.
Scorpio - The Seventh Doctor
Sylvester McCoy's Seventh Doctor was a cunning mastermind who rarely hesitated in manipulating friends and foes alike. Like other Scorpios, the Seventh Doctor was able to use his intuition to strategize and maneuver every situation to his liking, even his companions weren't safe from his machinations.
Scorpios have a strong intuitive ability, which allows them to read people as soon as they meet them. That skill is something they frequently use to their advantage, manipulating people or situations to their benefit.
Sagittarius - The Sixth Doctor
Colin Baker's Sixth Doctor was the ultimate extroverted outcast. His patronizing personality was only made worse by his skillful use of language, as the Ninth Doctor could bring most of his enemies to their knees merely by talking them into defeat. A skill is sure to make any Sagittarius proud.
Sagittariuses are intellectuals of the highest caliber. They are always seeking knowledge, though this tends to lead to them wielding the truth like a weapon, with little regard for the thoughts or feelings of the people they are interacting with.
Capricorn - The First Doctor
William Hartnell's First Doctor began as a grump, but as his relationships with his companions developed, he grew noticeably softer. In true Capricorn style, the First Doctor was driven by his sense of justice, answering only to himself.
Capricorns are ambitious and dedicated, usually motivated by an internal sense of duty. It takes them a while to warm up to people, though when they do, they are very loyal. Capricorns have a habit of repressing intense emotion, rather than sharing it.
Aquarius - The Ninth Doctor
Christopher Eccleston's Ninth Doctor had a capricious personality, and it could make him seem distant. He shunned the eccentric styles of his predecessors while hiding his pain under a sarcastic exterior. Except Rose, the Ninth Doctor loved humanity as an idea but seemed to care little for them as a whole.
Innovative and revolutionary, the Aquarius is often mistaken as being unstable or cold, which leads to self-imposed alienation, making it difficult for them to connect with others. The Aquarius will almost always go against the grain, no matter the cost, so when they find their people, they hold tightly to them.
Pisces - The Thirteenth Doctor
Jodie Whittaker's Thirteenth Doctor makes a perfect Pisces. As the show approaches the Centenary Special, she frequently shifts from youthful joy at each new experience to bone-deep weariness at all that is wrong in the universe. She shows boundless comion for her companions, while also interfering in their personal lives and feelings without a second thought.
Pisces are sensitive, empathetic, and have little to no boundaries. They are chameleons, changing parts of their personality to suit the situation or people they are with. A Pisces gives off the sense of being both old and young, and will often see signs in ordinary things.