If a dragon goes through an End gateway, another immediately spawns at (0, 128, 0 ) while the other dragon stays on the outer End islands until the chunks get loaded. If the player does not pick up the dragon egg and starts to re-summon the dragon, the dragon egg disappears. The four crystals placed around the exit portal then explode. Eventually, all of the end crystals point at the corner of (0, 128, 0) and the Ender dragon spawns there.

The top of each pillar explodes, destroying any player-placed blocks. When the dragon is re-summoned, the four end crystals point to the tops of each pillar setting off a series of explosions that resets the obsidian pillars, iron bars, and end crystals. Players can re-summon the Ender dragon by placing four end crystals on the edges of the exit portal, one on each side. This image shows how the player can arrange end crystals to respawn the Ender dragon. The Ender dragon spawns 20 ticks after an entity first arrives in the End, along with the bedrock frame for the exit portal.

Minecraft dragon skin with wings