It is possible, thanks to the magic of modding, to play Minecraft as any of the creatures in its world. Can you beat the game while playing as a fish? You can beat Minecraft as a fish.
I'm gonna change into a fish right now. Also just real quick guys, I know a lot of you will probably skip to the end to see if we beat the game or not but I seriously encourage you guys to watch the whole thing because it'll give you a full understanding of how hard this actually was and what we had to do.We genuinely thought it was going to be impossible.
Obviously fish in the world of minecraft have capabilities they do not have in our world, such as carrying large amounts of stuff and crafting more stuff, but within the logic of the Minecraft world it's still incredible.
