Request: Easy Way to have a boss summon enemies?

I'm using RPG Maker 2003... yes I know, it's archaic compared to the newer RPG Makers but I still like it and know my way around it a lot.  Also I went with it mainly because of the small resolution and I suck at drawing graphics for anything larger than 320x240.  Anyway.  Is there a way to make an enemy summon multiple enemies that were not present at the start of the battle?  I pulled it off doing one enemy but every time its summoned it shows the HP healing counter which I would like to do without and in my system it only supports one enemy and also the enemy has to be present at the very start of the battle... I can use an event in the battle to kill it immediately but you see it for a moment as the battle transition occurs and it looks half-assed.  Pardon my language but it does!  I was hoping maybe there's an easy way to pull this off because I have a boss I would like to have summon enemies.

Also, if there is a hard way I'd be willing to go that route as well since I only have to do it once anyway.

Well, I haven't used 2k3 for a long time, but if I recall, can't you:

create a monster troop with all the enemies that will appear. Right click the picture of each enemy and check the invisible box, then use Show Hidden Monster in a battle event during the battle to make them appear?

Yeah that works, thanks, I forgot how to hide a monster.  At any rate, is there a way to completely heal the monster when it is brought back to life under the guise of being summoned without RPG Maker showing the healing counter display that pops up on an enemy when you increase their HP in the events?