Ender Dragons take damage from things enchanted with the thorns enchantment, even if you are in creative gamemode.
If you don't feel like chasing the dragon, go to the portal in the middle of the island and execute the following command:
/data merge entity @e[type=ender_dragon,limit=1] {DragonPhase:3}Attachments
Comments 3
@@unknown Yup just tested it; still an issue in 1.13-pre5. (And honestly; why would it fix itself? 😛 But okay I'll update the affected versions)
Is this still an issue in the most recent versions (currently that is 1.10.2, or 16w42a) of Minecraft? If so, please update the affected versions and help us keeping this ticket updated from time to time. If you are the owner/reporter of this ticket, you can modify the affected version(s) yourself.