Not confirmed Rhyperior doesn't take damage from most attacks

[dylanwicorek]

The only attacks that i've noticed it's taken damage from are dragon, normal, and rock attacks

 

[Pyrithe]

I noticed something similar, not sure if it's related, but my Onix was fighting a Spinarak and it took no damage from Poison Sting, is it somehow relative to perhaps defense being too high so it literally takes 0 damage?