The Dark Mage is a mini-boss that spawns in the Old One's Army event during wave 5 in Tier 1 and during waves 4 and 6 in Tier 3. It will freely float a bit above the ground. It randomly chooses between three attacks:
- The Dark Mage summons Dark Energy, and hurls it directly at the player, dealing 80 / 160 / 240 damage.
- The Dark Mage summons a large rune, which then generates a large area of light that heals most NPCs in its 62.5-tile range (who have at least 30 maximum health, who deal at least 1 damage, and who are not a Dark Mage) by up to 500 health.
- The Dark Mage begins chanting, and a Dark Sigil will appear. After a short moment, Old One's Skeletons will appear from them. This attack cannot be done if there are more than 200 NPCs in the world.
- 黑暗魔法師將持續重生，直到級別 1 的第 5 波達到 99%。這使得擁有困難模式之前後期或更高級別的裝備的玩家可以刷它。
- 這個小 Boss 會掉落兩個寵物蛋：Gato蛋和龍蛋；不過，食人魔會掉落照明寵物飛眼怪蛋。
- 級別 1 中的黑暗魔法師掉落的寵物是所有由敵怪掉落的寵物物品中掉落率最高的之一。僅次於掉落自地牢守衛的骨頭鑰匙。
- On the 電腦版, the War Table, War Table Banner, Dragon Egg, and Gato Egg are not affected by Luck, unlike most uncommon loot drops. Thus, they will always drop at their listed drop rates.
- Dark Mage can't heal itself, other Dark Mages and Moon Lord
- If a boss reaches the second phase and then is fully healed by the Dark Mage, the boss will still maintain its current phase (with an exception like Santa-NK1, Plantera, King Slime, Queen Slime as it will convert into the first form after fully heal).
- Dark Mage的 怪物圖鑑條目：「A small, levitating sorcerer from Etheria who wields dark magic and can even raise fresh minions for the Old One's Army.」
- 《地牢守護者2（Dungeon Defenders 2）》Wiki 上的黑暗魔法師
- 電腦版 1.3.4：引入。
- 主機版 1.17：引入。