The Ball Bat is a recurring enemy in the Rosenkreuzstilette series.
The Ball Bat initially clings to ceilings or the bottoms of platforms, wrapped into a ball and immune to damage. Once the player comes near, the Ball Bat will detach and unwrap itself and slowly chase after the player. It is based on the Bubble bat enemy from the Mega Man series, which was introduced in Mega Man 2.
In Rosenkreuzstilette, they are found in the Imperial Training Hall (opening stage), the Snowfield (Freudia's stage), The Fortress City of Zuverburg (Sichte's stage), stages 2 and 4 of Zeppelin's Castle, and the second stage of the Iris Palace.
In Rosenkreuzstilette Freudenstachel, they appear in the Castle Grounds (opening stage), the Forest of God (Dolis's stage), the Zeppy Ruins (Schwer's stage), the Mountainside Dungeon (Grolla's stage), and the Phalanx Cathedral Ruins (Eifer's stage).