If you just want to look at the curious little fishes on your site too, you can have your own pond like this:
Just insert the following lines into your code! You can costumize the size of the panel by changing the width and height values, but it might not work as intended if you set them to too small.
<embed width="600" height="300" style="border-radius:50px; border:4px dotted grey" type="text/html" src="https://mircuskasarok.neocities.org/pond/embed_explanation/embedding">
I honestly started the whole thing because I wanted to experiment with the ripple effect as the circles appear after the cursor, the fishes only came as a second thought. I worked a lot on this program to make the movements of the fishes good enough, it required a lot of math. I drew the gifs with the different patterns, and I learned quiet a few interesting things about the coloration patterns of koi fishes. (For example did you know that the famous ones that have a single red circle on their head (look up tancho koi) are just simple red-white koi fishes, and the pattern can't be bred? It can only happen by luck.) I really loved making this project, and here are a few versions I uploaded before I settled on the one I linked from the main page.
Single fish Here there is only one fish yet. It has a small glitch in it that I corrected in later versions. Also, here the fish follows your mouse regardless of the distance.
Multiple fishes The other fishes are added, and they move independently, only the ones close to the cursor follow it. There is a set number of them.
Fishes come and go This is the version I decided to link from the homepage. Randomized fishes swim in, move around a bit, maybe examine your cursor, and then leave.
Fish leading game I started making a game version of the site, I wasn't satisfied with it, but you can try it here regardless. You have to lead the fishes into the sun-ring, there they shine up, and you get points for them. That's all, there is no end and no winning.