AMAZING ANIMALS 11 - ORIGAMI - INFLATABLE FISH (FROM A SQUARE)
Text-Only Tutorial copyright 2026 by Lindy van der Merwe
Extensive video instructions are available from the following link:
Paper to be used: Square, any size; use large paper to practice with at first.
Folding level: Beginner to Intermediate
Steps: 19
Description: This is an inflatable 3-dimensional model. The end result is a very recognizable fish with a puffed-up body and a flat-folded tail fin.
This is a great project for children and one that many adults might still remember from their childhood days.
If you are using two-sided paper, make sure that the side you want for the outside of the fish is facing up before you start to fold.
NOTE: This model starts from the waterbomb or balloon base. If you are able to achieve this without instructions, fold the base and then go to Step 9.
Step 1
Place a square of paper on your work surface and position it so that its edges are at the left and right, top and bottom.
Step 2
Bring the top edge down to meet the bottom edge. Crease and unfold.
Step 3
Bring the left edge over to meet the right edge. Crease and unfold.
Step 4
Turn the square over and position it so that its points are facing up and down, left and right.
Step 5
Bring the left point over to meet the right point. Crease and unfold.
Step 6
Bring the top point down to meet the bottom point. Crease and leave folded.
Step 7
Grasp the left and right points of the resulting triangle and push inward. The model should collapse along the pre-existing folds. The result will be another triangle shape that has one folded flap sticking out from the back of the model and another sticking out from the front.
Step 8
Fold the front flap to the left and fold the back flap to the right so that your model will lie flat.
The model will have one open end, which should be facing you.
Step 9
Next, grasp the left bottom corner of the triangle, top layer only, and fold it upwards and inwards to meet the top point of the triangle.
The bottom left edge of the triangle will come up to lie straight along the center vertical line of the model.
Crease and leave folded.
Step 10
Repeat with the bottom right corner (top layer only).
You should now have a diamond shape lying on top of a triangle.
Step 11
Fold the left and right points of the diamond shape towards each other and just slightly downwards. They should meet at the center vertical crease line with their points just touching.
The model will look better if these folds are not too straight, but slightly angled towards you.
Notice that these flaps are now forming pockets, which we will be using shortly.
Step 12
Grasp the two small, loose points at the top of the model and fold them downwards as far as they will go. They will fold along the top edge of, and cover the pockets you formed in the previous step.
Make sure to follow the contours of the pockets when you fold these points down. This will let them fit neatly and securely in the next step.
Unfold both flaps.
Step 13
With the fingers of one hand, Open the left side pocket slightly while grasping the left flap from the previous step with the fingers of the other hand, tucking it inside the opening below it.
Press flat.
Repeat with the right flap.
This step can be tricky to accomplish. Take your time and do not be afraid to open the triangles at the sides of the diamond shape a little to make things a bit easier.
Make sure the top triangles are neatly tucked in as far as possible and crease well.
The bottom or belly of the fish is now folded in place.
Step 14
Flip the model over from left to right to reveal a smooth triangle on the back side of the figure.
Step 15
Take the left corner and bring it over to the right and a little downwards towards you so the flap will just cross slightly over the center vertical line of the model.
A pointy flap will stick out towards you beyond the bottom edge of the main body of the figure.
Step 16
Repeat the previous step with the right triangle, folding it on top of the already-folded flap.
You will now have two long, narrow points overlapping each other down the center of the figure and crossing at the point nearest you.
Step 17
Take the top-most flap (the one that came from the right). Fold it back to the right at an angle. The fold line should start near the middle of the fish and angle outward, so the sharp point of the flap sticks out past the right edge of the body.
This should form the first fairly small triangle of the tail fin.
Step 18
Then, take the underneath flap (the one that came from the left). Fold it back to the left at the exact same angle, so its sharp point also sticks out past the left edge of the body.
Don't worry if the last folds feel somewhat floppy at the moment.
Step 19
Pick up your model. The hole will be at the 6 o'clock position. You may have to temporarily fold the tail fins back so they are out of the way at this time. Hold the model lightly by the sides and pull apart slightly while blowing forcefully into the open end to inflate the body of the fish.
If preferred, you can shape the model very slightly by pressing the tail and head areas gently to flatten them, giving the fish a more stream-lined, elongated shape.
Your final model should have the following features:
The Body: A rounded, hollow, air-filled capsule (like a small paper ball).
The Top (Back): It will feel like a continuous, slightly curved surface running from the nose to the tail.
The Bottom (Belly): You will feel the geometric ridges, folds, and pockets that form the closed cavity of the model.
The Tail: A flat, double-layered fin kicking out to the left and right at the very back of the puffed-up body, right above the inflation hole.
Don't be discouraged if the fish does not turn out perfect the first time. Precise folding, well-creased lines and some practice is needed to make this model turn out well.
Making origami accessible through text-based instructions.
For non-commercial use only.
Compiled by Lindy van der Merwe, June 2026
This text copyright 2026 by accessorigami.com and the author.