Looking at the recent Dunny Series 5, the characters done by Kathie Olivas seem to be the most sought after.  Here is a little information on Kathie Olivas.

Kathie Olivas is a multi-media artist who lives in Tampa, FL. Her work has been featured in numerous solo and group exhibitions across the US.

Her current work is entitled the “Misery Children”.  This series focuses on the social desire to assign “cuteness.” This often serves to make something innocent and more appealing, and as a result non-threatening. The characters evoke a reaction that reflects isolation, fear, and an uncertainty. This series presents a satirical look at how fear affects our sense of reality. 

Inspired by early American portraiture that often displayed children as small adults in an idealized new land, the characters parallel this vision within their own sense of post-apocalyptic conformity, uniquely documenting their own stories in a mysterious brave new world.

From her bio:

2000: Independent Study under USF Professors Bradlee Shanks and Victoria Hirt in experimental printmaking and photo-based processes
1999: University of South Florida, Bachelor of Arts Cum Laude
1997: Residency at the National Gallery of Art, Washington, DC (with Graphicstudio)
1996-1997: Elective studies at Graphicstudio: The Institute for Research in Art, Tampa, FL

Kathie is married to Brandt Peters .  They met at Ybor City’s goth club The Castle. Brandt grew up in Los Angeles and has worked in the movie industry as an illustrator and animator. Olivas received her MFA from USF and managed a gallery where she showed and collaborated with a group of “Lowbrow” Tampa artists. The two were living and working together within a month of meeting, and married within a year.

Not only do they live and make art together, but they have day jobs creating sets and props for the same theme park design company. The connection with their art has deepened in the work they have created since they met.
Cartoonish animals and children are common themes for Olivas. These bunnies, boys and girls may have started out cute, but modified to add muzzles and dunce caps, limbless , or with mouths zipped or bolted shut, they are ultimately repulsive.  We want to look away.