A mix of a demon and a devil. Usually a deevil comes in the form of an innocent being. The creature lures you in with their cute smile or doe-like eyes, then attacks when their prey is most vulnerable.
Daisy the puppy is quite a deevil.
That midget who bit me is a deevil!
Get away from the deevil!
Run, the Doblet is a deevil!
You are being such a deevil today.
God, I hate deevils, they are evil!