Because the work is not in the public domain, any free PDF must be offered with the explicit permission of the rights holders. Below are legitimate routes you can take:

El Capibara con Botas (English: The Capybara with Boots ) Author: Mira Canion Language: Originally Spanish (novice-level reader); English version may exist but is less common Genre: Children’s fiction / Language learning reader Target Audience: Beginning Spanish learners (ages 8–12)

Since a free stolen copy is unethical, here is how you can legally get the English content or equivalent value.