Who is Draco Malfoy from Harry Potter and the Deathly Hallows and what is their importance?

Draco Malfoy is Lucious' son. He belongs to Slytherin House, and he and Harry are rivals. Harry, however, proves to be merciful to him many times. Draco tries to kill Harry more than one occasion, and Harry regularly saves Draco's life. At one point, he even saves Draco from another Death Eater, who has mistaken him for a Harry Potter supporter.