In her human form, Camilla takes on the apperance of a beautiful young woman with a slender yet curvy figure similar to that of an Umbra Witch. She has long dark brown hair, silverish grey eyes and slightly pale skin. She wears a brown brotherhood dress which features a hood with a simple choker that features a single green gem
In her true form, Carmilla appearance changes. She now wears a nun's habit with the front split open to partially reveal her midriff and cleavage. Her skin becomes paler to a ghostly white while her eyes change from silverish grey to a demonic pitch black with red irises. Her choker also becomes more elaborate and embedded with red jewelry.
As a demon, much of Camillas personality is twisted. She cares little for life as she has no problem killing any human. She is intelligent, manipulative, seductive and deceptive
Despite this, she possess some traits that is similar to sympathy, as she tortured Frankenstein for centuries for his inhumane crimes, fulfilling the oath she made as a human to make sure he paid for his crimes. She also acts as a mother to Laura, showing she has motherly instincts.
Carmilla also is a seductress. She attempts to seduce Gabriel when he confronts her for the first time, and does so again nearly a thousand years later. While it is not proven, there are subtle hints that she may have had a romantic interest in Gabriel. She attempts to seduce him the first time they meet and offers for him to stay with her for eternity, saying that she can show him "many pleasures". Throughout their first fight, she also refers to him frequently as "my Gabriel". She also was visibly frustrated when she realized he was collecting the pieces of the God Mask to bring back Marie. During her second encounter with Gabriel, she kisses him on the lips, and claims "I am yours now". She is angered further when Gabriel drinks Marie's blood a second time, and right before Carmilla is killed, she tries to kill Marie, probably out of spite since she couldn't have Gabriel. She seems to have wanted to keep Gabriel, as she was using her blood to make him loyal to her and her alone, showing a very dangerous obsession and abusive side.