These disguises (or costumes) are found in the Collections tab of your UI rather than an item in your inventory. Hats were enabled for the screenshots, but the hats can be hidden.
- Skeleton Polymorph ~ acquired from the quest ‘The Bargain’s End‘, Shadowfen.
- Golden Saint ~ acquired by reaching Veteran Rank 2
- Dark Seducer ~ acquired by reaching Veteran Rank 8
- Mannimarco ~ acquired by reaching Veteran Rank 10
- Mask of Cheerful Slaughter ~ acquired by 9 months of sub