Cuca is a recurring antagonist of the novel books of Sítio do Picapau Amarelo (Yellow Woodpecker Ranch) writed by Monteiro Lobato. Based on a Brazilian folklore legend's character she is a witch who kidnaps and eats naughty children. In the books she marked her first appearance to kidnap one of the protagonists in one of the chapters of the book "O Saci" in 1921 (in that book, she is one of various villains of Brazilian folklore, but when this book become a movie, named "O Saci" in 1951, Cuca appeared in it as the main antagonist). Her iconic appearance is best rememberer in popular culture from a TV series adaptation produced in 1970. In this version she became incarnated as an anthropomorphic alligator with blond hair, acting as the main villain in the story. With the success of this adaptation in the TV series, Cuca returned in all other adaptations of the Sítio do Picapau Amarelo, including the 2001 and 2008 version and the cartoon series in 2012 (and in a comic book launched between 2006 and 2008, based in the 2001 version, the most famous version in the XXI Century, and because this, inspired the cartoon series).
Although in the books she is shown as a serious and cruel witch, in the TV adaptations Cuca has an angrier and incompetent personality. She can be considered a bogeyman for always abduct children to devour them, but can never eat anyone. She also shares a rivalry with Emília the Ragdoll, one of the main characters who often foils her plans.
While in the original TV series she had a fat and ugly appearance, later depictions gave her a more slender body with a more feminine appearance, even wearing a red dress which gave her a dominatrix feel. In the latest TV series, she is given a hunchback henchman named Pesadelo (Nightmare), who is never present in the books and in the folklore.