The Ender Dragon is still able to target players with the Invisibility effect. This is very unlike the behavior of other mobs which cannot see the player when invisible. The earliest version affected found by the previous reporter, Rebecca, was 1.14.

Steps to reproduce:

• Start a new world to creative mode and give yourself permanent invisibility

  /effect give @p invisibility infinite

• Teleport to the end

  /execute in minecraft:the_end run tp 0 100 0 

• Switch to survival mode
  -> Observe that the Ender Dragon is still able to target the player despite them being invisible.