I just want to point that everything depends on the situation. But what the heck, you don't want that explanation , nobody does. So i'll just get to point.
For the Hit Points:
I suggest, using instance variables for that. For example:
Instance Variable named "Health".
For the Spawning:
I suggest timer for the time(x) interval of spawn.
And arrays for your spawn count & spawn coordinates and order(x,y,z).