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.
Teratology is the study of abnormalities of physiological development. It is often thought of as the study of human congenital abnormalities, but it is broader than that, taking in to account other non-birth developmental stages, including puberty; and other non-human life forms, including plants.