Step 1 : Introduction to the question "5. In J.K. Rowling's "Harry Potter and the Prisoner of Azkaban", a Boggart turns into Ronald Weasley's worst fear. What was the phobia that haunted him? (The name of the phobia is derived from the Greek word for spiders)"
...1. Anemophobia 2. Arachnophobia 3. Arachibutyrophobia 4. Atephobia Arachnophobia is the fear of spiders (derived from the Greek word for spider, "arachne"). That is why the Boggart turned into a spider in the third part of the "Harry Potter" series. Boggarts turn into your worst fears.