"Necropolis" - changes to creatures of levels 6-7.

Is this the one that the Altgreyd's horses have, the demons?

No. The horses have an ability called "Withering Aura," but "Terrifying Presence" is not found in standard creatures. The ability works like this: when a creature with this ability attacks, the attacker may become frightened and run around the arena (if susceptible to mind control).