Whose stuff? Esmeraude/Emerald of the Black Moon Clan.
From? Anime: Sailor Moon R
Season Episode 38: Series Episode 84 -「ワイズマンの魔手!ちびうさ消滅」 or “Wiseman’s Evil Hand! Chibiusa Disappears”
What? Black Crystal Crown…of doom. Wise Man tricks Esmeraude into wearing this black crystal crown, promising her a future as Queen. Sadly, she turns into a dragon and is promptly defeated by our heroes.
GIMME! A crown of your own for the days when you feel like the most unwanted, unloved, misunderstood villainess.
Etsy - patent leather headband for $48 or a similar elastic one for $15 or this amazing clip for $12.
For something more subtle, how about Stainless Steel Spike Earring for $11? Or a Black Spikes Elastic Stretch Bracelet for about $7?
Just remember: Prince Dimande will never, ever love you.