Originally I just had the grumpy one as a doodle in one of my sketchbooks, but while working on the sculpt I came across a photo of a very content lion, which I figured would contrast nicely with the grumpy one.
https://www.devriesarts.com/
Regular zbrush render with a touch of photoshop
Zbrush NPR render paint style
Zbrush NPR render pencil style