Argoan

The Argoans are a humanoid species from the planet Argo.

Weaknesses
In the DC animated universe supergirl is portrayed as being vulnerable to kryptonite, this is different in the tie-in comics where she is unaffected. Aside from kryptonite the weaknesses of the Argoans seem identical to that of Kryptonians.

Culture
Not much is known about the culture of the Argoans, but they were at least equal to krytpon, as well in the "Superman Adventures" comics it is shown that they have a reverence for Rao (indeed Raoism is said to be their primary religion), the patron deity of the Kryptonians, thus hinting at a common ancestry.

History
Roughly 300 years before supergirls arrival on earth General Zod overthrew the planets leading council in a violent coup. Many suffered and died during the "Great Darkness" the decade-long rule of Zod.

Finally, after assembling an armada to attack krypton Zod was betrayed by his own staff, and captured by the kryptonian council. He was banished to the phantom zone, the only Argoan to ever be punished in that manner.

Argo seemed to have a long period of prosperity that ended when krypton was destroyed. the planet was flung out of its natural orbit and slowly began to freeze, being completely frozen over within four years killing almost every Argoan save for Kara In-ze who survived in suspended animation.

Known Individuals
Please note that these characters are typically kryptoninans (or non-existant) in most continuities
 * Dar
 * Del
 * Kalya
 * Kala In-ze
 * Kara In-ze
 * Noma
 * Tala
 * Zod