Filigree Feather is an unlockable trinket in The Binding of Isaac, added in the Afterbirth+ DLC.

Angel statues will drop items from the Angel Room item pool instead of Key Pieces when defeated, unless Isaac already holds one of the Key Pieces.

This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this trinket for the previous Repentance version, check this page instead.

Acquire Key Piece 1 and Key Piece 2.

The following special synergies and interactions for Filigree Feather have been documented.

* Note that not all possible synergies and interactions are listed here.

Below is the Internal Item Description as shown in-game.
Note that some stat changes are not displayed here. Please see the main description for the full effects.

Filigree Feather

• Defeated angels will drop angel room items instead of key pieces
• If a key piece was previously collected, angels will spawn the other key piece before producing angel items
• Golden Trinket (without Mom's Box): Angels drop a half soul heart when killed
• Mom's Box: Angels drop a half soul heart when killed
• Mom's Box + Golden Trinket: Angels drop a soul heart when killed

• Check out the trinket description on the external Isaac Wiki.