Origami Remora

This is the fish that sticks on larger creatures, like sharks. The funny thing is the suction disc is actually a highly modified dorsal fin.

Design

The defining feature of this creature is of course the suction disc, along with slender body with some fins at the end. To make the suction disc, I would use a long flap and pleat it. The challenge for me was the hind section which has adipose fin (top), anal fin (bottom), and caudal fin (tail).

I figured out that the anal fin can be made using a sunken sawhorse molecule:

The paper that got pushed up is suitable for this fin. I can place this part near the end of diagonal and the excess paper in the corner can be used for caudal fin. For the adipose fin, I thought to somehow use the excess paper in the edge. Therefore I didn't plan it in the crease pattern. For the remainder of this post, I will omit the shaping creases shown in the picture above.

Moving to the head part. I need a pair of pectoral fins near the suction disc that will expand like wings, and a pair of pelvic fins right below it. I also need to form the mouth and possibly eyes. Actually the fish has slightly shorter upper lip compared to the lower lip. It is going to tricky to get that correctly in the crease pattern, so I would simply create a longer flap and somehow split it. The stick figure for the head part should look like this:

With trial and error, I came up with this arrangement. I started with quarter bird base for the suction disc, mouth, and pelvic fin. Then the rest is improvised.

This arrangement makes it easy to put the sawhorse that were planned for the hind part. I extended the lines from pectoral fin and eye until they meet at the red point (shown below) and close the paper boundary. Finally, plug the sawhorse.

Here is the final crease pattern, along with the reference lines which I recently learned to find using https://www.folders.jp/reference/reference.html.

The final design is quite simple. After giving some test folds, I am not sure if pleating the suction disc is the best option. I tried several method like pattern grafting or simply making a zig-zag creases. In the end, pleating gave the best result. For the mouth, I made an open sink then spread the top like how it was done on my cordyceps' mushroom.  

I have been learning a lot from Origami-dan Discord channel. The reference finder above is something I got to know from that channel. Apart from that, I also learned using Orihime. It is a super powerful tool to design a flat foldable origami model. I studied computational geometry back in the college, and I know how tricky it is to make something like Orihime, so big amazement to the developer. It takes time to learn Orihime but totally worth it. The crease pattern on top of this post is drawn using that software. 

Fold

I used a leftover single tissue from making cordyceps with 15 cm x 15 cm size. Ideally double tissue will be better, but I actually enjoy folding with thin paper as long as the model doesn't need to support its own weight, or it will be thick enough to be able to do so.

Care should be taken to not fold the head part too flatly, otherwise the model will be weird if seen from the sides. I purposely expand the layers to give the head a bit of volume.