No, it's not a comma splice. A comma splice is a term for joining two (unrelated or unlike) sentences together with a comma without adding any kind of conjunction:
Clowns wear funny noses, I don't like pie.
What you've done is place a comma between a verb and its subject, which is in most cases not allowed. Just get rid of the comma:
The words demoniacal corpse suggest that the creature is unnatural and inhuman.
Commas in this position are occasionally used to avoid misinterpretation or make a sentence easier to read:
Most of those who can, work at home.
(The Cambridge Grammar of the English Language, p.1730)
Here, the comma prevents you from misreading work at home as part of the subject and then getting confused when the sentence ends early. But outside of exceptions like this, commas are almost always a bad idea between a verb and its subject.