They only spawn during one of the Ender Dragon's special attacks, either by morphing an Enderman into a small group of bats, or by simply spawning nearby a player if there are no Endermen in reach.
The only reason for bats' life is to heal the dragon, which happens by stealing player's health and sacrificing itself. They still have slight randomness to their movements just like regular bats, but eventually get close enough to the targetted player to perform the attack.
In order to prevent the dragon from healing, the bats can be killed by a single hit. It may require a little bit of practice to stay at the right distance where you are able to attack them but they aren't, as most of the time they are in a group of 3 or more.
- It is easy to notice them in the End as they spawn purple portal particles at their position
- Unlike regular bats, these will never go into "hanged state"