She is very sweet and caring. She likes to help her brother with his insanity. She can get very emotional when she overthinks. She cares deeply for Sans and Papyrus, and gets emotional when thinking about them.
She has no hair and white bones. Her fingers levitate over her actual hand. She has white heart-shaped pupils.
She often wears a variety of dark blue/bluish grey, hence her nickname. She wears a bluish grey T-shirt under a denim jacket, a navy blue skirt and grey sneakers. She commonly carries a clipboard.