Final answer:
Lord Voldemort's four official titles in the Harry Potter series are Heir of Slytherin, Dark Lord, Lord Voldemort, and Voldemort. His snake-like appearance and malevolent actions throughout the series clearly position him as the antagonist. Character development is crucial, with many characters' roles changing from Harry's perspective, although Voldemort consistently remains evil.
Step-by-step explanation:
Tom Riddle, also known as Lord Voldemort, held several titles throughout the Harry Potter series by J.K. Rowling. The four official titles he held were: Heir of Slytherin, Dark Lord, Lord Voldemort, and simply Voldemort. His looks were characterized by a pale, snake-like appearance with slits for nostrils, red eyes, and no hair, which underscored his transformation from a charismatic young man into a symbol of pure evil. The author J.K. Rowling makes it clear that Voldemort is an antagonist through his behavior, which includes a cold, cruel demeanor, a disregard for human life, and his quest for power, which often involves the harming or manipulation of other characters.
Character development is a critical theme in the Harry Potter series, which includes Harry's own growth from a loner to a heroic, sociable figure capable of admitting his mistakes. This is highlighted by his evolving perceptions of other characters as he learns that the apparent 'bad guys' may actually be 'good guys.' In the case of Voldemort, however, he remains consistently an embodiment of evil throughout the story, which is a storytelling technique used by Rowling to emphasize the struggle between good and evil.