Siphon Life

Vendor: Darahir

Zone: Dalaran

Cost: 40 (unlimited supply)

Drop: Maexxna [??+]

Zone: Naxxramas

Approximate Drop Rate: unknown

Pet Battle: [3-6] Silverpine Forest; [3-6] Bloodmyst Isle; [6-7] Hillsbrad Foothills; [12-13] Eastern Plaguelands

Trading Card Game: Worldbreaker

Drop: High Astromancer Solarian [??+]

Zone: Tempest Keep

Approximate Drop Rate: unknown

Pet Store 

Pet Battle: [1-2] Undercity; [1-2] Tirisfal Glades

Pet Battle: [23-24] Twilight Highlands

Pet Battle: [20-22] Borean Tundra; [20-22] Howling Fjord; [21-22] Sholazar Basin; [21-22] Grizzly Hills; [22-23] Crystalsong Forest; [22-23] Zul'Drak; [22-23] The Storm Peaks; [22-23] Icecrown; [22-23] Dragonblight