Which is correct?

The former - but only because it's part of a saying, not for any inherent grammatical reason. The saying in full is "Speak of the devil and the devil shall ... something or other". ("appear", I think. Anyone care to complete this?)

The phrase is used in the following context. Suppose you were talking about Santa Clause, and - while you were having the conversation - Santa were to actual

We say "talk of the devil", we can (rarely) add this "and you see his horns"

apparently the French have an idiom almost exactly the same, "Parles du diable et on vois ses cormes" (excuse random spelling errors!)

"Speak of the Devil and he is sure to turn up". There are many instances in religion of the utterance of names of demons or unsavoury creatures being sufficient for their manifestation.

In popular culture recent examples are Michael Keaton's character "Beetlejuice" and the horror film "Candyman". This belief in the power of a name to somehow conjure its owner has given rise to its use i