Definitely a normal hellbrute.... thanks for chiming in. For those asking, I believe this is on the Plague Marine page.
Is this new? It definitely looks cool in this picture, but could be a conversion. As far as we know there is no new Dreadnought in the new index for Death Guard, but as we will be seeing in the near future with the Redemptor Dreadnought for Primaris Marines, I would not be surprised if there was a new entry for Chaos Marines.
Thank you to the readers that brought this up.