Carmilla is a tall demoness with a thin hourglass built, light grey-magenta skin, and long, thick white hair with black streaks. Her hair is usually kept into a pair of large beehive-like horns by thin, ballerina-like black ribbons, but when she lets her hair loose, it reaches down to her ankles and is slightly messy.

She has black lips and a darker-colored marking resembling a mask enveloping her eyes, which have white irises and red sclera.