Sunfury

The Sunfury is a rare drop flail category weapon from Bone Serpents in The Underworld. It's an orange flail that emits light during attack and deals 40 points of damage, but can hit multiple enemies at once and one enemy twice (or multiple times in the case of a boss).

When the ball goes too far from the player or hits a block, it quickly retracts.

Here is a video taking a look at the Sunfury