Wormtongue speaking to Théoden by the great Alan Lee

My suggestion to all the kings out there: If your advisor is named “Wormtongue”, you should be suspicious of the things he says.

To be fair, even though every place I see him he is referred to as Gríma Wormtongue, that actually wasn’t his name. It’s just what everyone but the king called him. His actual name, as far as I can determine, is just Gríma, son of Gálmód.

From the The Lord of the Rings Sketchbook by the great Alan Lee