Sonja is a fictional character from the Underworld series of films. This character is the daughter of the vampire elder Viktor, introduced by flashback, in Underworld. Red Sonja, the She-Devil with a Sword, is a fictional character who first appeared in Conan the Barbarian #23 (Marvel Comics).
tetralogy (plural tetralogies) 1  A set of four works of art that are connected, and that can be seen either as a single work or as four individual works. They are commonly found in literature, film, or video games. ( 2 medicine) A combination of four symptoms.
Tetraploidy is a condition in which there are four sets of chromosomes in a single cell instead of the normal two sets. The total number of chromosomes per cell in tetraploidy is 92 instead of 46. The affected babies are usually miscarried early in the pregnancy or die within the first days of life.