🐲Mojang considered adding a red dragon as a less dangerous mob in the overworld, but it never made it into the game.
🐋Baby dolphins were planned but only exist in the bedrock version of the game, with no plans to add them in Java.
🌩️The Great Hunger, a mob that burrows into the ground and attacks the player, could be a useful way to enchant items.
🔥The wildfire, a powerful blaze variant, was considered but was ultimately not added to the game.
🦆Ducks were debated to be a separate mob from chickens, but Mojang decided against adding ducks to Minecraft.