Pet/follower who is not a party member, but participates in battle?

I have looked to see if this has been implemented, but could not find. I was wondering if I could have a "pet", who is present along side a party member in battle, and participates in battle, but is not a party member.

Examples would be:

A wolf by the side of a beastmaster
A demon by the side of a warlock
A monster by the side of a summoner
A fairy flying by your side

The look would be like something below.



I was thinking that the mechanic would be just like you have a passive spell on you in the beginning of a battle and there is a glowing animation on you,
the "pet" could be just like a passive spell, which is always on. But the animation would actually be a character which goes out and attacks instead of just pulsing a glowing color.

In my game, I have a demon with a warlock, and a summoned angel by the summoner, but I do not want them taking up a party slot.

Thanks!

EDIT: Wrong chamber... ignore this

'Game Mechanics Design' is for looking at aspects of game play at a more conceptual level. "How do I...?" (implementation) questions go in the appropriate Support forum for the engine you are using.

As this cannot be done by default and you are using MV...
[move]JS Plugin Requests[/move]

Not exactly the same thing, but for a Beast Master or a Summoner, you can take a look at Summoner plugin by SRD