Set enderdragon to invisible

I was wondering if you can set the enderdragon to be invisible using packets. I'm trying to do this so I can use the enderdragon health bar for displaying things without just spawning the dragon under the in some far up or down place. But using the methods here and switching it to use the enderdragon it is no longer invisible.

 

http://wiki.vg/Entities#Entity_Metadata_Format

 

I know that but it seems that the enderdragon just can't be read as invisible as the client or something because the same packet for invisibility is being sent as was for the wither.

 

Give it a potioneffect.

Code:java

enderDragon.addPotionEffect(new PotionEffect(PotionEffectType.INVISIBILTY, time, amount));

 

The just spawn it at -500 y.

 

Why you dont send the packet to the player that shows the enderdragon healt bar? Why should you need the enderdragon too?