Minecraft 1.12.2, Minecraft 17w50a, Minecraft 1.13.1, Minecraft 1.13.2, Minecraft 18w43c, Minecraft 18w48a, Minecraft 18w48b, Minecraft 18w49a
Converting a librarian into a zombie villager and back has 50% chance to become a cartographer which is not supposed to happen.
- Dig a hole 6 x 4, spawn 4 librarians
- Let zombies turn the villagers into zombie villagers
- Cure the zombie villagers and wait
→ Check the professions and observe how the villager is a cartographer