A while ago there was a thread discussing a potential animated series:
It ultimately ended on a stalemate of "We should not force Klei to spend more time on this than the rest of their projects". Since then they have made the decision to no longer be an indie company in order to not worry about finances as much and to maintain the quality of life of their employees. Hopefully this means that they will be able to work on projects much more freely and efficiently.
It's not clear what a potential series would look like, but Klei has said that they have a couple of ideas up their sleeve. I completely trust that they will be able to create something fantastic and worthwhile no matter what they decide on. If Klei are up to the request and most importantly: if working on an animated series is still in interest to them, there is nothing stopping us from reaching out to a big streaming company and potentially achieving the beginning of a DS animated series.