Leinfors' Hair Protector

Like the rest of the developer wardrobes, this one only comes out of the bags Hardmode bosses leave behind, on a rare roll, and Queen Slime is skipped. Those bags exist only in Expert and Master worlds, so a Classic character cannot collect it. Any Hardmode boss counts and the odds do not scale with the difficulty, so farm whichever one you can kill fastest. The roll also hands over Leinfors' Prehensile Cloak, which is a real accessory rather than a costume piece.

Leinfors' Luxury Shampoo is the piece worth putting in an accessory slot on purpose. It sets sparkles in your hair, and because the effect needs light to register, it vanishes in an unlit cave and only reads properly above ground or beside torches. The clothing is social slot only, and the male and female sprites are identical, so it looks the same on any character.

The design leans on Alucard from Castlevania: Symphony of the Night, which is why it reads more gothic than the other developer outfits. The mark on the shampoo bottle is the old planetary symbol for Saturn, which alchemists also used for lead, a joke that only lands if you know the symbol.