I wanted to make a cushion for ages! What stops me - details mainly. What shape and size, how to deal with opening and so on... But eventually I am there!
It's circular inside with solid fins. Wool is merino mainly but of different grades and quality (all my leftovers used!), silk noil in circular details, merino/silk blend on fins, piece of dark blue silk fabrik on the top (to reduce pilling).

These pictures are to show the size. It's approx.32cm x 32 cm without fins and tail:

This is the bottom and how I dealt with opening - 3 large snaps.

The weight is 130 g.
I like it and am going to make more! Watch this place!