In short: i didn't like the movie, but the vfx are terrific. Anyone knows if the four armed creature is all cg? I have read some article about it, but i didn't understand if they used a practical puppet only for reference or they actually used it in the final shot. If it is all cg, it's remarkable.
I think you are talking about Lady Proxima, the worm-like creature Han visits. That is mostly a practical puppet, with CG lower arms and some 2D dialogue imagery onto the puppet.
Here is a quote from Ian Failies when he conducted an interview with Rob Bredow at Thrillist:
It might seem like the perfect candidate for a CG character, but again, a practical puppet was the starting point. Digital effects came into play to realize two of her lower arms when motors controlling the appendages during one day of the shoot weren't working, and for painting out the rig and puppeteers controlling Proxima on the set.
Digital also had a role to play when, late in post-production, it was decided to change some of Lady Proxima's dialogue. In other similar situations, a visual effects studio might build a complete CG version of the creature's face in 3-D to portray the new lines. But the filmmakers were incredibly happy with the way the practical puppet looked, so they had ILM make the dialogue changes simply by painting the different face shapes in 2-D onto the existing images.
Here is the article(its's also on my second post from the top of the page here)
https://www.thrillist.com/entertainment ... t-creation