It imitates the black tail worn by Wikebine in Morocc.
Unfortunately, it doesn't seem to work ...

Critical +7.
Decreases after attack delay by 3%.

When equipped with Wickebine's Black Cat Ears:
Increases critical damage by 10%.

If Refine Level of Wickebine's Black Cat Ears is +7 or higher:
Critical +5.

When equipped with Black Cat Ears Beret
Random chance to transform wearer into Wild Rose for 5 seconds when dealing physical damage.
During transformation: All Stats +8.
Every refine level of Black Cat Ears Beret, increases the trigger chance.

[iRO Description]
Not Available