Who played Frodo Baggins in 'The Lord of the Rings: The Fellowship of the Ring'?

Who played Rubeus Hagrid in 'Harry Potter and the Sorcerer's Stone'? In which film is Rubeus Hagrid a character? Who played Lord Voldemort in 'Harry Potter and the Goblet of Fire'? In which film is Lord Voldemort a character? 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'? Who played Legolas in 'The Lord of the Rings: The Fellowship of the Ring'? In which film is Legolas a character?