Lord Voldemort

Tom Riddle, Lord Voldemort was a wizard and the Dark Lord of the Death Eaters.

Biography
See Canon Wiki

Relationships with Magical Creatures

 * Nagini: A Magical Viper who was Voldemort's closest companion and the only being whom he ever truly loved, if in a twisted way; some theorize this may have been platonic romantic love in some way.
 * Salazar Slytherin's Basilisk: An ancient Basilisk whom Voldemort controlled to do his bidding during his school years.
 * Horcruxes: Created seven from his own soul.
 * Horcrux Wraith: Became one himself from 1981 to 1994.
 * Portrait Voldemort: A Portrait based on Lord Voldemort.
 * Voldemort's Vampires: A small army of Vampires who served Lord Voldemort during the First Wizarding War.
 * Giant Colony: The colony was swayed to Voldemort's side during both Wizarding Wars.
 * Dementors: The Dementors of Azkaban made a deal of mutual assistance with Lord Voldemort during both Wizarding Wars.

Canon

 * Tom Riddle on the Harry Potter Wiki