Monster Spawner (Diablo III)

The Monster Spawners are uncommon totem-like monsters from Diablo III, that look different but have the similar function of summoning various monsters around them.

Zombie

Rotting Corpses

Iron Maiden

• The first spawner are the Rotting Corpses found rarely in The Weeping Hollow. It spews multiple Crawling Torsos and auto-destructs if getting close to it.
• The second spawner is the Iron Maiden found in the Halls of Agony Level 1-2. Most of them on these levels are just destructible objects, but sometimes a couple of cultists are seen sacrificing someone to an Iron Maiden which then starts to spawn Voracious Zombies from it. It won't spawn more if it has two of these zombies near it, which makes it somewhat of a negligible danger.

Skeletal Guardian summoning circle

Skeleton

Both Skeletal Guardians and Gatekeepers are Undead, which suggests that they may be somewhat sentient reshaped Skeletons.

Skeletal Guardian

Gatekeeper

Activated Pillar

• The first spawner is the Skeletal Guardian (not to be confused with the similarly named monster type), three of them sometimes spawn in the Cathedral Level 2. They work rather weirdly: a Skeleton attacks them which summons new Skeletons in a summoning circle that they surround. These Skeletons can quickly pile up into a horde, but after some time the attacking Skeletons become uninterested in the Guardians.
• The second spawner is the Gatekeeper found within Cathedral Level 4. Sometimes a Resplendent Chest can be found within this level which lowers under the floor if interacted with, then these Gatekeepers rise up from four holes around and start summoning Skeletons, Skeletal Archers and Skeletal Shieldbearers with blue magical swirls. After the destruction of these structures the Chest rises up, ready to be opened.
• The third spawner is the Activated Pillar found within The Royal Crypts. They are normal pillars until activated by the Skeleton King in Reign of the Black King quest. They summon Skeletons and Skeletal Archers and are the most damage resistant of the spawners. Outside of the quest they stay unactivated and harmless.

Khazra

Khazra Totem

Khazra Totem summoning circle

• The Khazra Totem is found on the Leoric's Hunting Grounds in the number of three. It works like the Skeletal Guardian: a Dark Moon Clan Warrior or Impaler hits it and then new ones spawn from a summoning circle. It's circle looks like a more advanced version of the Guardian one.