When I morph into Ender Dragon form, I take constant damage up until I shift out or die.
Is this a bug or intended?
I'm on version 1.11.2.

I think it's Tough as Nails conflict with Metamorph. There's an option in Metamorph mod options to disable health modification. If you'll turn that on, it should be solved, but you'll have always 20 health.

Minecraft 12.1. I dont have tough as nails but I too die if I dont morph into something else. I will try the health modification. Ok i tried it with the config change I am still getting lots of damage from something

My brother's server is running Minecraft 1.12.2 with Metamorph 1.1.7 and McLib 1.0.
Tough as Nails is not installed.
Upon morphing into the Ender Dragon, I take continuous damage until I morph out. Sometimes I suffer considerable knockback, from various directions.

I suspect that this issue is related to 116 and the @kreezxil's comment for 115. There may be some relation with issue 100 - although that is a stealing action rather than an attack...