A is for Annika Hansen. Also known as Seven of Nine.
B is for Bob, who worked at the Cetacean Institute in San Francisco in 1986.
C is for Captain Christopher. First Human to officially meet a Vulcan. Although he doesn't remember it.
D is for the Dax Symbiont.
E is for El-Aurians, a humanoid species of "listeners" that was almost wiped out by a Borg attack during the late 23rd century. The small number of survivors, which included Guinan, spread out across the galaxy.
F is for First Maje Cullah. Seska's pet Kazon.
G is for Gregory Quinn, high-ranking Admiral at Starfleet Command during the mid-to-late 24th century.
H is for Hanar. A Kelvan that Dr McCoy tricked into taking an excessive amount of stimulants. Making him go crazy.
I is for Izar, the Federation colony that was the homeworld of the legendary Captain Garth, one of the most famous and revered Starfleet officers of the 23rd century.
J is for Janos. Ensign Janos. A genetically altered Mugato.
K is for Kashyk. Sexy fascist Devore inspector who was no match for Janeway.
L is for Landru. Turned out to big a giant box with blinky lights. And apparently ran on Windows Vista.
M is for Mugato venom.
N is for Naomi Wildman. Daughter of Sam, friend of Neelix & Seven and captain's assistant.
O is for Odonna of the planet Gideon. Classic use of the honeypot.
P is for Parmen, the authoritarian and strong-willed leader of the Platonians who tried to force Dr. McCoy of the Enterprise to remain on their world to serve as his personal physician.
Q is for Qualor II.
R is for Reman dilithium mines.
S is for Sybok - in search of Sha Ka Ree.
T is for Tsunkatse. Martial art invented by the Norcadians.
U is for Ulis, a mid-22nd century Ferengi pirate who was one of the first members of his species to encounter humans from Earth when his ship and crew attempted to board and plunder Enterprise NX-01.
V is for Vendikar. Close neighbor and at war with the planet Eminiar 7.
W is for Warriors of the Klingon Empire.
X is for Xindus.
Y is for Yelgrun, a Dominion Vorta who in 2374 was sent to oversee the prisoner transfer of Ishka of Ferenginar for the Vorta Keevan.