Basecoat the skin with Word Bearers Red . The colours are pretty close, so you can probably get away with one quick coat.
Wash the skin with 1 part Darkoath Flesh , 1 part Garaghak's Sewer and 10 parts Contrast Medium .
Drybrush with Tuskgor Fur .
Drybrush lightly with Squig Orange and add highlight manually with a brush, where you cannot drybrush.
Selectively highlight with Kislev Flesh .
Add very small highlights of 1:1 Kislev Flesh and Pallid Wych Flesh and specular highlights of pure Pallid Wych Flesh in selective spots.
Pink Flesh
Basecoat with Bugman's Glow .
Wash with Reikland Fleshshade .
Highlight with a 1:1 mix of Bugman's Glow and Cadian Fleshtone .
Apply smaller highlights of Cadian Fleshtone .
Selectively highlight with Kislev Flesh .
Finish with dots of Kislev Flesh mixed with Pallid Wych Flesh , where needed.
Fleshy Belly/Tentacles
Basecoat with 4:1 Ungor Flesh & Wild Rider Red .
Drybrush raised details with pure Ungor Flesh .
Add a touch of White to the Ungor Flesh , then drybrush lightly, builging up the volumes.
Wash all of the area with 2 parts Reikland Fleshshade and 3 parts Lahmian Medium . The idea here was to unify my drybrushing a little and get some easy shading in there too. You could always make the mix heavier on the Reikland Fleshshade , if you wanted a richer colour.
Mix some Ungor Flesh 1:1 with White again, and selectively highlight the membrane, within the previous step.
Finish with very small highlights of White .
Dark Blue Carapace
Basecoat with Stegadon Scale Green .
Recess shade with a mix of Stegadon Scale Green and Abaddon Black .
Add chunky edge highlights of Thunderhawk Blue to all of the plating. Also add striations on the edges of large plates with the same chunky lines.
With Fenrisian Grey , edge highlight it all again with fine lines. Place these fine lines within the striations from the last stage too.
Apply selective edge highlights with Blue Horror . Make these highlights very selective or even specular highlights. These should be placed on the edges of the striations too.
Finish with a few specular hihglights of Ulthuan Grey on points and particuarly strong striations.
Black Bone Claws/Weapons
Basecoat with Abaddon Black .
Glaze highlight raised areas with Corvus Black & Stegadon Scale Green mixed 1:1.
Add chunky highlights with Stegadon Scale Green .
Apply fine highlights with a 1:1 mix of Incubi Darkness and Administratum Grey .
Selectively highlight with Administratum Grey .
Finish with very small highlights of 1:1 Administratum Grey and White . Specular highlights of pure white are probably a good idea on points too.
Yellow Eyes
Basecoat the eye with Yriel Yellow .
Highlight a smaller area towards the front with Dorn Yellow .
Finally pick out a specular highlight with White Scar .
Teeth
Pick out each tooth with a couple of layers of Ushabti Bone .
Add a smaller layer of Wraithbone to make each tooth look more cylindrical.
Finally, add specular highlights of White Scar to the points.
Tongue
Basecoat with Screamer Pink .
Optionally, you can glaze towards the base of the tongue with Druchii Violet if you wanted. I did.
Glaze towards the tip with a few passes of Pink Horror .
Mix Pink Horror 1:1 with Kislev Flesh and apply smaller highlights.
Now do the same with smaller highlights of pure Kislev Flesh .
Finish with a dot of Wraithbone on the tip, to add shine.
Green Smoke
Basecoat with Caliban Green and Ushabti Bone , mixed 1:1.
Wash the smoke with Biel-Tan Green . Try and pull the pigment towards recesses and areas where the smoke is thickest.
Mix a pure white, like White Scar , into the base mix gradually amd build up highlights. Apply them towards the tip of the smoke, furthest from the source.