Thank you so much for all the positive comments. I always check it several times before I post it, and it is logical, only the last two dots are ambiguous.
I actually thought it was an interesting and fun puzzle. Some second order logic, but that just makes it more difficult, not illogical. I would prefer not to have that tiny ambiguity at the end, but otherwise, great job!
After that, there's only 2 interchangable dots which are easily solved.
Tanja, thank you - I really like the image!
C1: R10-14
R20: C3-8, C10-11, C13-15
It's a good looking elephant, worth the effort.