I’ve been almost constantly playing with a simple fish form I discovered a few weeks ago and have finally began to understand the geometry of it. You may laugh, but it has proved quite tricky to pin down and even my mate Wayne agrees 😉
One thing I’ve tried is using 60 degree geometry and this has produced a fish that is quite flexible in terms of how the flaps can be arranged. Here’s a crease pattern and a few of the variations. I’ve sent a copy to the wonderful Bob Neale in case he can come up with story to go with it. The final variation (lower right) is in fact an equilateral modular, complete with flaps and pockets!