|The Duke of Flies|
| The Basement|
The Catacombs (Double Trouble)
Boss Challenge Room
Normal Enemy (Later Floors)
| Boss Pool|
The Duke of Flies is a boss that appears in The Basement. Compared to most other bosses, the Duke has little health and cannot even attack on his own. He makes up for this by summoning attack flies for both offensive and defensive purposes. The Duke of Flies was a boss in the original Binding of Isaac.
The Duke of Flies has three attacks which he can perform while he floats around the room slowly.
- While moving around the room, he will cough up attack flies that will orbit around him, blocking shots.
- Occasionally, he will cough up a moving attack fly that will move toward Isaac
- His third attack consists of him coughing which will spread the flies orbiting him outwards, freeing them to move towards Isaac.
- Upon death, he will explode into more flies, and all orbiting flies will be free to move towards Isaac.
- Green Duke of Flies spawns Moters instead of Large Attack Flies and shoots blood shots in eight directions when coughing.
- Orange Duke of Flies is larger than normal and spawns Suckers instead of Large Attack Flies.
- The stitching under the Duke of Flies' mouth is an autopsy stitch, an incision in the shape of a Y. The incision allows passage to the cadaver's insides; when the autopsy is complete, it is stitched back up.