First Test Design
At the very beginning it was planned to make the Grievers as big robotic machines. However I had already created this Test Design, before I got the job, which showed the hybrid creature idea from the novel. I presented the design to Wes and he loved it. We collaborated on a few changes and attachments afterwards in order to enhance the final Griever design. Slugs and coconut crabs were a huge influence for me in finding the overall body shape. The head was a bit tricky, since in the book they have no face, only a big ugly mouth. It's basically a mixture of caterpillars, bulldogs and even piranhas.
I did plenty of these different pose sketches, which illustrated how the creature could move. The wizards from Method Studios enhanced the movements to perfection.
Since we see the Grievers mostly in the dark, Wes wanted to find a way to illuminate them with some kind of 'light dots' and sensors. This is one of a few options that I had sent to him. One idea was to put these lights underneath the slightly translucent skin which would constantly move in one direction.