Tom Riddle isn't mentioned at all in Prisoner of Azkaban. In Goblet of Fire, the Riddle house, Tom Riddle Sr.'s grave, and even Voldemort make an appearance, but not Tom.

Tom Riddle's mother seduced Tom's wealthy Muggle father with a love potion. While some fans dismiss this as just one more bit of magic in the world of Harry Potter, the ugly truth is that Tom ...