|The Duke of Flies|
| Floors of
| The Basement|
The Cat. (2x)
| Base Health||110|
|Items Dropped||Boss Pool|
During the battle, The Duke of Flies will perform on of many attacks as he bounces around the room. The attacks The Duke of Flies can perform are as follows:
- The Duke of Flies will spawn several Attack Flies to circle around him.
- The Duke of Flies can send these Attack Flies to attack Isaac.
- The Duke of Flies will spawn a large Attack Fly to attack Isaac.
The Duke of Flies has two different variants he can spawn as. They are as follows: