Hi folks.

I'm creating the Amazonian Conclave subclass of ranger from Odyssey of the Dragonlords. The subclass has a beast companion (a stimfay) whose hit points are equal to 15 + ranger level. Now, I've created the stimfay as a monster, and I can import it as an "extra" without issue. All the other subclass features are working perfectly, but I can't for the life of me figure out how to get the hit points to calculate automatically. 

Is there a trick to doing this? If so, I've missed it completely!

Any help would be greatly appreciated!

As far as I am aware that is not currently possible within the system. It doesn’t auto scale HP for any “Extras.” The creature’s MAX HP can be adjusted directly on the character sheet though by either the player, or the DM.

Ahh, that makes more sense. I thought I was going crazy! :) 

I've ended up creating a specific, named version of the critter for the ranger my wife is playing, and I'll just manually adjust its hit points as she goes up in levels. 

Thanks! :)