Someone didn't tell Yoko that Halloween was over a month ago.

The shrieking septuagenarian showed up for an art event in Miami on Thursday in this Willy Wonka meets the Mad Hatter meets Elvira ensemble ... which caused shrieking of another ilk.

Yoko's top hat, sunglasses and plunging neckline create a fashion trilogy of terror that leaves us wishing she'd dress more species-appropriate. Imagine!