Monsters such as GIANT LIZARD, HUGE GELANTINOUS CUBE, and other relatively high CR monsters have been spawning with a shit load of cure serious potions.
While this may be to make them more challenging, I am fairly certain its a bug and needs to be looked into asap before more player deaths occur to this traumatizing sight of a 3 intelligence ooze downing potions.
I've noticed a lot of them using "potion of lesser dispelling" on my PC, which somehow is casting dispel magic.
The great lizard is an unique incident. Huge Gelatinous Cube I need to check.
This also happened with Savage, Undead Pack Leaders. They spammed Healing and one even used a blurring potion I believe. DM Halfbrood can confirm this.
So as not to clog up the forums with another thread - Undead Seaguls are sneak attack-able.
I'v encountered Giant Undead Bears that use blur and much to my amusement cure serious potions.
Some of the H'bala minions I've encountered that are labeled as undead seem to not have immunity to critical hits.
Undead Stargazers
Undead Pirate (scythe)
The H'balan undead aren't immune to crits and sneak on purpose.