As for the rule, see Wikipedia's article.
Clicking a head of hydra, you can cut the head.
By dragging and dropping a carrot onto Hydra's head, you can make Hydra eat it. However, there is no effect of it.
This program was created by Tatsuya Goto in 2024.
This program uses the matter.js, which is a JavaScript physics engine.
This program uses sound materials from the following site.
