Gender -- Male
Race -- Frost wyrm
Affiliation(s) -- The Scourge, Kel'Thuzad
Former affiliation(s) -- Blue dragonflight
Occupation -- Guardian of Naxxramas, former agent of Malygos
Location -- Frostwyrm Lair, Naxxramas

An ancient servant of Malygos, Hand of Magic, Sapphiron was a blue dragon who lived with a powerful brood in Northrend by the Dragonblight, where he communed with the ancient spirits of the dead dragons.[citation needed] Sapphiron was magnificently powerful, and protected the lands of Northrend as best he could. Though Ner'zhul's malevolent influence defiled the Dragonblight, Sapphiron and his brood continued to guard his hoard of treasure from any and all intruders.

Sapphiron and his brood lived in relative peace until Prince Arthas, champion of the Lich King, was suddenly called back to Northrend to save his weakening master, Ner'zhul. After three weeks at sea, the Death Knight landed on the shores of Northrend near Sapphiron's frozen lair, and was greeted almost immediately by the Crypt Lord Anub'arak, King of Azjol-Nerub, another powerful servant of Ner'zhul. Anub'arak had sensed Sapphiron nearby and suggested to the young Death Knight that perhaps by equipping themselves with the ancient blue wyrm's treasures, he and Arthas might be better prepared for the perilous journey through the underground kingdom of Azjol-Nerub to Icecrown Glacier. Arthas agreed, and boldly journeyed into Sapphiron's lair with Anub'arak.

The two servants of the Lich King fought their way through Sapphiron's minions till they finally reached the great blue dragon himself. Sapphiron confronted the undead as they approached him. He found Arthas's honesty about killing him and stealing his treasure quite "refreshing". Sapphiron and his fellow dragons attacked with all their might, unleashing their strange, cold frost magics upon them. In the end, despite all odds, Arthas was victorious, and Sapphiron was defeated. As a final, clinching victory, however, Arthas used what remained of his dwindling necromatic power to recreate Sapphiron as a frost wyrm to serve the Scourge.

Sapphiron, now a mighty frost wyrm, assisted Arthas in destroying the Naga and Blood Elf forces blocking the passage to Azjol-Nerub. Sapphiron was called upon again to destroy the dwarves guarding the gates to Azjol-Nerub, but the great dragon was left outside of the tunnels, where he guarded it against all who would disturb his new master.