Wormtongue a cannibal?

[Inziladun]

Originally Posted by Kuruharan

The parallel to Gollum really is quite striking.

The degree of desire is not comparable, since the One Ring had a power to cause obsession beyond one's ability to resist, but it seems greed and a wanting for something he did not have (Éowyn) could indeed have put Wormtongue into a similar state as Gollum.
Bending all one's will toward "possession" has a degrading effect, regardless of the initial motives behind the want.