Time is short today, but this is such an easy one!
When doing a story about sci-fi bounty hunters, it's a given that one of the team is going to be a robot. It's in the rules. We could face heavy fines if we didn't include one.
In my mind PK stands for "Perpetual Killing". He's programmed to kill and he has no understanding of feelings or emotions - and more importantly no desire to. He cannot be reasoned with, or persuaded, and he is prone to random acts of violence. And in true R2D2 fashion he's also a bit of a Swiss Army knife. If the story requires him to produce a sprinkler that sprays acid then he can. If we need a tool to emerge from a panel then he can do it. But he's not there to drive the plot - he's generally there to obstruct it.
From a design perspective, my only real notes to Grug were that I didn't want him to be humanoid. I really wanted something that looked menacing, but more like an appliance and did not have distinct limbs, and certainly not any kind of recognisable face. I think we probably discussed the idea of him hovering too, as i didn't want him to be bipedal (something we're going to have fun with later on).
He was the last character to be designed, and all of the others went through many revisions. PK went through one. Grug sent me this:
And I said, "That's great! Can we turn it upside down?"
And that's PK! Those two little screws inadvertently became his fear-inspiring "eyes".
No colour tests on this one either. I knew he had to be red and that's what I did:
HOLY CRAP. IT'S AS SIMPLE AS THAT!