Dragon Zombies can be damaged while idle (until they try to attack the player)

[DrippingYellow]

As far as I know, Dragon Zombies are meant to be invulnerable to attacks except when firing energy balls at the player. However, it seems they're shootable by default until they notice the player. This can be exploited if the player uses long-range weapons like the Fireball or the charged shots of the Spur.

[TrashboxBobylev]

Fixed in 1.43 beta-4