Seriously. Every koala pic in the book has an expression that can only be described as "derp".
Except for one, who appears to be laughing boorishly at an awful joke.
An unfortunate fact about koalas: they are very hard to draw without making them turn into Fozzie Bear.There's a certain inherent puppety felt nature to those padded cheeks and floofy ears. I would try to overcome it, and express the true savage beastial nature of the dropbear, but..nah. That pretty much IS their nature, really.
One thing I find interesting as I go on this project: my right hand, while clearly weaker and less practiced than my left, is also clearly still MY hand. My essential style doesn't seem to change much. But the way I look at my references changes a lot from hand to hand; I have very little urge to cartoon or compose, working right handed, but I do have a more conscious awareness of light and basic shape. Not expected, but interesting...