Who played Lord Voldemort in 'Harry Potter and the Goblet of Fire'?

Who played Severus Snape in 'Harry Potter and the Sorcerer's Stone'? In which film is Severus Snape a character? Who played Rubeus Hagrid in 'Harry Potter and the Sorcerer's Stone'? In which film is Rubeus Hagrid a character? In which film is Lord Voldemort a character? Who played Frodo Baggins in 'The Lord of the Rings: The Fellowship of the Ring'? Who played Gandalf in 'The Lord of the Rings: The Fellowship of the Ring'? Who played Aragorn in 'The Lord of the Rings: The Fellowship of the Ring'?