Origami Inside Reverse Fold (Method 2)
These are small techniques that are often used in origami. You can find them in instructions for making different animals, where they help to make a head or tail.
This fold is not complicated at all but can be intimidating to those who encounter them for the first time. Learning how to fold the inner and outer folds will make it easier to understand the instructions and you will be able to make many different origami without much trouble.
Now turn to the opposite corner: make a diagonal fold, bigger this time. Dip the corner between the layers of paper, you already know how to do this.
See what you got? It looks a lot like an animal with a head and tail.