The Nieces and Nephews

We have eight nieces and nephews. Since they don't belong to us -- we just get to borrow them for a while -- it's necessary for us to introduce them to you under assumed names. They are:

Frak, 16
Frik, 15
GG, 4
Kal-El, 2
Uno & Duo, 18 mos.
Thor, 3
OLu, 3