The Fish Imp is one of the several types of Imps in Rule of Rose, making its debut in the "Mermaid Princess" chapter. Their only other appearances are in the cafeteria and upstairs bathroom of the Rose Garden Orphanage during The Funeral chapter.
The Fish Imps could be symbolic of Clara and her implied sexual relationship with Hoffman. Their legs are bound together with rope, alluding to the Mermaid Princess boss fight at the end of the chapter. When touched, the Fish Imps flail about, possibly representing Clara's frightened and timid nature, most likely as a result of prior sexual abuse.