Bloodstained: Ritual of the Night/Bridge of Evil

Kunekune
Kunekune is a hidden demon found on the train in the Bridge of Evil. You can't encounter it the first time you ride the train. Miriam can sit in one of the chairs near the left side and she will gaze out the window. After some time, the demon will appear off in the distance and get closer when Miriam blinks until there is a jump scare. Then it will attack.

Kunekune is a much higher level demon compared to the others in the area. It will curse Miriam and deal damage if it looks directly at her. Since it stays on the ground, one strategy is to use the Invert shard to safely attack from the top of the train.