A mask is commonly associated with disguise, concealment, theatricality and decoration. But in the Batman mythos, the mask motif is typically used as an expression or component of actual identity. Batman’s cape and cowl gradually exceed mere costuming to become Wayne’s real persona, with Bruce Wayne becoming the mask.
His rogues gallery features many people who wear a mask not as an alternative identity or pseudonym, but as an aspect of their true self.
The mask defines them...
The Red Hood
Penguin is so called because of his physical appearance and clothing.
Even the Ventriloquist, as Scarface is engaged as a mask for Wesker.
And Killer Croc’s deformity is a form of mask.
The bandages worn by Hush are indicative of not only his medical background, but also his hidden nature, and eventual reconstructive surgery transformation into Bruce Wayne’s image.
The Mad Hatter adopts the clothes and personality of the Wonderland character.