From Wikipedia, in folklore, a mermaid is an aquatic creature with the head and upper body of a female human and the tail of a fish. Mermaids appear in the folklore of many cultures worldwide, including the Near East, Europe, Asia, and Africa. Surely you have heard of this mermaid story.
Usually the kids are familiar with this mermaid character. What about your child? If your child is fond of mermaid characters, you can make Corchet mermaid by first reading this Amazing Crochet Mermaid Tail Blanket Patterns Tutorial.