Consider the matched pairs below. What should be written next to Dracula?

DEVIL - LIVED
DIAPER - REPAID
DRAWER - REWARD
DELIVER - REVILED
DRACULA - ?

Answer:

Nothing. It should be left blank.

The first four pairs of words are "semordnilaps" - the second word's letters being the exact reverse of those of the first (but making a different word) - as it might be reflected in a mirror. According to the enduring story by Bram Stoker, Dracula has no reflection in a mirror.

Credit:
Idea of leaving blank squares in a puzzle for Dracula's reflection - David Kwong
NY Times Crossword - October 31, 2013

Note from JA: "Semordnilap", or "palindromes" in reverse, is a word coined by Lewis  Carroll.  A palindrome is a word that reads exactly the same forward and backward (LEVEL). A semordnilap is a word that can be read exactly backward, but it's a different word (PART - TRAP). I prefer to call semordnilaps "perfect anagrams."