Difficulty:Peaceful (Lock)
I was looking at the End to see the Enderdragon's new behavior, and there were 2 things I didn't spot at the End island: 1. The Enderdragon, and the portal you throw an enderpearl through to go to the end dungeons. Therefore, you cannot get the credits in peaceful mode.
same over here but also in difficulty hard i had to spawn in the dragon with the clay block creeper face but than the health bar of the dragon wont show up on the screen
i made a end portal in creative wile mi difficulty was on Hard and entered the end portal wile in creative andthe dragon didnt spawn
edit: but in a second test world i made the dragon did spawn but than the difficulty was on normal and i was also in creative