I absolutely love the design of this thing. From the horns to the sprouting tentacles, the Hellbrute is the epitome of Chaos as a malevolent, ever-changing force. While it's perhaps not suitable to some of the more conservative Chaos legions, it works pretty well for most warbands, and for a snap-fit model included in a starter set box, the level of detail is pretty much incredible.
Regarding the paintjob, I've based the thing white and used Troll Slayer Orange for the armour plates and Warplock Bronze for the armour edges. I decided to go with red color on the daemonic flesh and used Mephiston Red with Bloodletter highlights - I'm very happy on how the glaze made the organic parts stand out, especially in the chest area. The wet look of the tentacles has been done using Gloss varnish.
It's no big secret that the back side of this miniature is not as well-detailed as the front, especially when it comes to the huge blobs of flesh around the spine - which is, in my opinion, a very cool part of the model and at least works well as a distraction from the less detailed parts.
I haven't modified the miniature much, though one thing I really wanted to do was to add a Heavy flamer to its arm - after all, what screams The Pyre more than a Dreadnought armed with two fire-based weapons? I went with a rather simple conversion - after cutting away the chains under the left arm, I've glued on an imperial guard vehicle heavy flamer and covered it with tubes made of green stuff to give it a fused look. The result looks pretty good and works great for barbecue.
Basing has been done in the same style as the rest of my The Pyre warband - as scorched earth, though at first it seemed a little boring, so I've added a dead marine under the creature's feet (and to taunt a friend, I've chosen a Dark Angel for the victim). I really like these weird mutated feet by the way - they help to enforce the overall "living metal" feel of the miniature. I know I'm in the minority here, but I really wish these would have been kept in the Hellbrute box as an option... oh well.
One final thought - I really wish this miniature had Monstrous Creature rules instead of Walker. Afterall, it's apparently much more organic than a Dreadnought suit, and a change to MC could make an insteresting spin on the classic Dreadnought rules. However, for some odd reasons, in 40K Aliens-style walker suits and Eldar giant mecha get MC rules, while this does not. That's just classic Games Workshop game design.
Anyway, thanks for reading!