The Month of Adar
According to The Book of Formation (Sefer Yetzirah) Each month of the Jewish year has a corresponding color, a letter of the Hebrew alphabet, a zodiac sign, one of the twelve tribes of Israel, a sense, and a controlling organ/limb of the body.
Adar is the twelfth month of the Jewish calendar.
The word Adar is cognate to the Hebrew "strength" (אדיר). Adar is the month of good fortune for the Jewish people. The sages say of Adar: "Its mazal [fortune] is strong."
Purim, the holiday of Adar, commemorates the "metamorphosis" of the Jews' apparent bad fortune (as it appeared to Haman) to good. "When Adar enters we augment with joy." The festival of Purim marks the high point in the joy of the entire year. The Jewish year begins with the joy of the redemption of Pesach and concludes with the joy of the redemption of Purim. "Joy breaks through all barriers."
The joy of Adar is what makes the month of Adar the"pregnant" month of the year (i.e., seven of the nineteen yearsin the cycle of the Jewish calender are "leap years," "pregnant" with an additional month of Adar). When there are two Adars, Purim is celebrated in the second Adar, in order to link the redemption of Purim to the redemption of Pesach. Thus, we see that the secret of Adar and Purim is "the end is wedged in the beginning."
Letter: Kuf (ק)
The letter kuf means "monkey" (קוף), the symbol of laughter of the month of Adar. In accordance with the idiom "as a monkey in the face of man," the kuf also symbolizes masquerade, an accepted custom of Purim. Before the miracle of Purim, God Himself "hid His face" from His children Israel (in the entire story of Purim, as related in the book of Esther, His Name does not appear even once). By initially hiding one's true identity, pretending to be someone else, the innermost essence of one's true self becomes revealed. On Purim, we reach the level of the "unknowable head" ("the head that does not know itself nor is known to others"), the state of total existential hiddeness of self from self, for the sake of "giving birth" to one's ultimate self anew.
The word kuf also means the "eye of a needle." The sages teach us that even in the most irrational dream one cannot see an elephant passing through the eye of a needle (see here for more on this teaching). Yet, on Purim one experiences this great wonder, which, in Kabbalah and Chassidut, symbolizes the truly infinite essence of God's transcendent light entering into the finite context of physical reality and revealing itself in full to the Jewish soul.
Mazal: Pisces (Fish)
Fish are the creatures of the sea, which in Kabbalah is a symbol for the "concealed reality." Likewise, the souls of Israel are likened to fish that swim in the waters of the Torah. The true identity and fortune of Israel is invisible in this world. The revelation of Purim, the revelation of Israel's true identity, reflects the revelation of the World to Come (the miracle of Purim is understood to reflect in this world the ultimate miracle: the resurrection in the World to Come).
The singular form for "fish" in Hebrew is דג. It represents the tikun, the rectification of worry; the three letter root of "to worry" is דאג (pronounced da'ag). In the Bible, the singular form of fish (דג) actually appears once written as the root, worry (דאג).