I saw this recipe for sale for $25.
While I don’t think my looks as good I was able to do to it at a considerable savings.
I got a brand new "Marvel Legends: Nuke" figure for under $10 from amazon.
It comes with two heads and other accessories and the buck I will use for another custom later.
I used a light grain sandpaper to remove the existing flag design from Nuke’s face, followed by a little rubbing alcohol. The nuke head fits on the Venom body’s neck peg perfectly.
The skin tone paint I found that matched well is called "Kislev Flesh" from citadel paint -which I also purchased from amazon for $6.50. I drew the dark eyebrows with a fine tipped sharpie.
I used black Sugru brand molding for the symbiote tendrils.
For practice I flesh painted the face that has the robotic features exposed.