I was playing creative mode, and decided to spawn some Wardens to kill the dragon. They did the Sonic Boom attack and stuff, but the dragon didn't receive even a point of damage.

Expected behavior:

• Warden does sonic boom attack on the dragon
• Dragon loses HP
  Shown behavior:
• Dragon doesn't lose HP.

How to reproduce

• Create a world in creative mode, and go to the end
• Spawn wardens next to the dragon
• See the wardens try to kill the dragon, but no HP is being lost