I decided to challenge myself and my printer with this job, and it worked!!
The most tricky part was the small tentacle pieces, which scared me a lot as I've never printed anything so little before.
For each tentacle I divided the pieces in 3 groups, each one printed at a different layer height for best results:
1-10: 200 µm
11-20: 150 µm
21-32: 100 µm
The head was also printed at 200 µm layer height, 20% infill.
After the printing I've spent several hours carefully removing the rafts.
And the most important thing: I had to use a hair dryer to fit the pieces together; as the small ones break if not, while the big ones were impossible to join.
I will paint it when I have some free time ;)