A pillar, about 30 feet high and 10 feet in diameter, is situated on a plain, hill, or large clearing in woodlands. It has been there for centuries. No one knows where it came from. It is inscribed with strange runes, that match no known language. Anyone who comes within 100 feet of it must make a saving throw vs. magic, or be compelled to approach the pillar. This saving throw must be made each round that the person is within 100 feet of the pillar. The pillar also affects animals, monsters, and even insects.
When the creature touches the pillar, it immediately goes berserk. It will attack anyone nearby, friend or enemy, with whatever is at hand. Affected people may not use spells, only melee combat. The berserker will continue to attack any living creature nearby until it dies. The berserker will not eat or drink, just wander out from the pillar, killing as it goes. A Remove Curse spell will grant the affected person or creature another Saving Throw.
No known magic has been able to destroy the pillar. Even wishes fail. It is a powerful artifact, that is truly too dangerous to use.
In some worlds, a paladin order or similar organization sets up a perimeter to prevent creatures from being affected. Unfortunately for them, birds, ants, bees, and other such creatures still reach the pillar, and then end up attacking the guardians.