"Tokiko" is a popular fan name; 'toki' means crested ibis, a bird which she resembles in appearance. Her true name is unknown, but she is sometimes (more properly) referred to as "Unnamed Book-Reading Youkai" (名無し本読み妖怪).
While shown as a weak youkai, after retaliating and causing damage to Reimu Hakurei when she originally thought the fight would be an easy one, she at least proved more formidable than Reimu first thought.