Cancer

Cancer (キャンサー Kyansā), "The Giant Crab" (巨蟹宮 Kyokaikyū), is a Celestial Spirit that is one of the 12 Golden Zodiac Keys. His key is currently owned by Lucy Heartfilia.

Appearance
Cancer dresses in a way reminiscent of a hairdresser, His hair is black and braided in red cornrows that end in a shape that resembles crab's pincers. Like Warren Rocko, he has thick lips. He always wears a blue striped shirt and dark trousers with two aquamarine stripes each side, also wearing boots in his feet. In his pants there's a ring chain in the right pocket and a hairdresser tools' bag in the left side of his belt. He wears a golden necklace and it's commonly seen with his two main weapons: Scissors. The color of his eyes is unknown because Cancer always wears sunglasses with green lens. He also has six crab legs that appear from his back.

During Lucy's fight against Flare Corona, Cancer appeared with a different outfit. He now wears a coat designed with Cancer's symbols on it. Also he wears shoes instead of boots, and his scissors are larger and more rectangular. Despite a less sharp format, the scissors were able to cut a very powerful Hair Magic spell.

Personality
Cancer has a very "cool" personality, he isn't very emotional or hotheaded.

Happy first thought that Cancer would end his sentences with the word -kani (crab); however, Cancer actually says -ebi (shrimp) at the end of his sentences. This shocked and displeased Happy. In the anime, Cancer acts differently in the presence of Erza. He acts in a gentlemanly manner and ends his sentence with -choki, meaning snip instead of -ebi. Erza made this suggestion during the struggle against Eisenwald. Her "not abolishing the opposition" and strict personality made an impression on Cancer, so much so that he even gave her a bouquet of roses.

History
Cancer used to be owned by Layla Heartfilia. Before her death, she passed on her keys to different owners. Eventually, when Lucy Heartfilia became older, she was given Cancer's key, along with Aquarius's key.

Daybreak arc
Cancer is first summoned to fight Everlue. However, he thinks he is being summoned to give Lucy a haircut. After the confusion ends, Cancer helps Natsu Dragneel defeat him by cutting off what is left of Everlue's hair and mustache.

Lullaby arc
Lucy summons Cancer to get rid of the remaining Eisenwald members (and also to make a good impression on Erza). He cuts through several of the enemies' weapons with his scissors.

Galuna Island arc
Lucy summons Cancer again to battle the Moon Drip worshipers. He seems to have gotten a small crush on Erza, as he presents her with roses before following Lucy's orders, much to Lucy's embarrassment.

Tower of Heaven arc
Cancer is briefly used to defeat some tower guards by giving them bald haircuts. He later brings Lucy a new set of clothing.

Oración Seis arc
Cancer is briefly used by Lucy, along with Taurus and Sagittarius, to stop the Naked Mummy Guild from robbing the Love & Lucky Guild in Acalypha. Once again, he defeats the Dark Guild members by giving them bald haircuts.

Edolas arc
Cancer is briefly used to cut Lucy Ashley's hair, and he always asks her if she really wanted that, because in Earth Land, girls don't do that too often.

Tenrou Island arc
Note: Events in this arc occur only in the anime and do not constitute canon material.

Key of the Starry Sky arc
Note: Events in this arc occur only in the anime and do not constitute canon material.

Grand Magic Games arc
Cancer celebrates Lucy and her friends' return from Tenrou Island when Virgo brings them to the Celestial Spirit World. During the celebration, he does Wendy's hair. During the Grand Magic Games, Cancer is summoned by Lucy during her fight with Flare Corona, when he successfully nullified Flare's Hair Shower - Wolf Fang and cuts a good part of Flare's hair.

On the seventh of July, Cancer is summoned to seal the Eclipse Gate with the other twelve Ecliptic Zodiac after both Lucy and Yukino combine their Magic power to save Crocus. After appearing, Cancer and his fellow Spirits fly straight at the Gate, succeeding in pushing the two doors shut and thus preventing any more Dragons from passing through.

Eclipse Celestial Spirits arc
Note: Events in this arc occur only in the anime and do not constitute canon material.

Sun Village arc
Lucy summons Cancer at the Sun Village whilst she, Wendy and Flare are battling the trio of treasure hunters from Sylph Labyrinth, as Flare's hair attacks are being disrupted by Hiroshi, who is using his sword to cut her locks. Telling his master that she can always rely on him with anything to do with hair, Cancer proceeds to wash and massage Flare's hair, allowing her to regrow it and continue fighting.

Tartarus arc
A week after Tartarus' defeat, Cancer is summoned by Lucy so that he returns Wendy's hair length back to normal. He then asks Lucy whether she wants a haircut herself.

Magic and Abilities
Enhanced Speed: Cancer appears to be remarkably dexterous and fast, being capable of performing swift hand movements, and wielding his signature scissors with great speed: he has repeatedly proven himself able to cut down enemies' hair with extreme accuracy, not leaving a single snick on their head. He does it in a single instant, appearing as though as he struck them only once, while in fact he has performed a number of separate cuts. Cancer's rapidity is enough for him to shave several opponents in mere seconds, not leaving them the time to fight back.

Hair Growth: Scalp Care: With hair being his specialty, Cancer can make others hair grow in a short amount of time by washing and massaging their scalp. It does tend to make them feel comfortable as shown when he help grew back Flare Corona's.

Immortality: As a Celestial Spirit, Cancer cannot die, unless he is somehow forced to stay in the Human World. Furthermore, as his owner's Magic Power grows stronger, so does Cancer.

Equipment
Scissors: Cancer is Lucy's hairdresser because of his weapon which seems to be two large pairs of scissors, with crab-claw design handles, which he can also use to cut hair. Lucy uses Cancer to cut her hair or to make a new hairstyle for her or her enemies. Cutting an enemy's hair seems to knock him out. It is also shown that his scissors are sharp enough to cut through weapons such as swords and hammers.

After Lucy powered up by unlocking her "Second Origin," Cancer apparently gets new scissors. This pair of scissors is longer, with a square-tip, and doesn't have a crab-claw design on the handle.

Special Mission: Beware of Guys Who Show a Keen Interest!
After Lucy convinces herself that Natsu is going to ask her out, Lucy calls Cancer to cut her hair, but punches him away as she wonders what she is doing.

Happy in Boots
Happy captures Cancer and Virgo in his net and presents them to the king and princess of the kingdom on behalf of his master, Natsu.

Fairy Academy - Yankee-kun and Yankee-chan!
Cancer assumes the role of being Lucy's hairdresser. He is called to do Erza's hair for her date with Sieg of Era Academy. Cancer also appears as part of the Fairy Academy staff during the assembly called by Carla for the delinquent students, though it is unknown what his actual role in the staff is.

Quotes

 * (To Lucy Heartfilia) "What kind of hairstyle would you like today? -ebi"