Ancient mages are monsters found in the Ancient Prison. There is no Slayer requirement to kill them.
They attack with blood, ice, shadow and smoke spells like those in the Ancient Magicks, effectively being able to freeze you, heal themselves, lower your stats and poison you. Using Protect from Magic is highly recommended, although it won't stop any of the secondary effects, such as freezing or poison. The poison starts at 88 damage.
They can drain a small amount of prayer points with their attacks, as well.
They are often near Ancient rangers, who will attack if the player gets too close.
Unlike the other inhabitants of the Ancient Prison, ancient mages will remain stationary on their spawn location unless attacking a player. They have some of the lowest wander radiuses for an NPC.
Ancient mages will be unaggressive towards players if the player is wearing the Shard of Zaros.
Their most common drop used to be 25 astral runes. However, they use ancient magics which don't require astral runes. This drop has now been made much rarer and its quantity is reduced to 15.
Ancient mages can drop coins in quantities of 1337, which means "leet".
They have an irregular attack speed, much like Cave horrors. Sometimes they will attack at a speed of 6, sometimes at a speed of 5.