First, prepare a square piece of paper.

Diagonal pairs are folded into triangles.

Open.

Fold the top down along the crease.

Fold up the lower edge along the crease in the same way as in the previous step.

Then align the edges on both sides and fold them in half.

Fold the small corner inward and upward.

Then fold the head of the waterfowl out and it looks like it's coming out.

Finally, the big horn is folded inward and upward, and it becomes the tail of a waterfowl, which is a very realistic waterfowl.