NOTE: For some reason, the File Images aren't working for me right now, so I will reupload pictures at a later date.
There is a linked Youtube video in case the images don't show up for you. Also, see the Bethesda.net XB1 pictures linked in the Mirrors.

A metal cat that shoots impossibly large balls of plasma which shoot plasma as the projectile goes by.
Also, finicky suicide plasma cats.

I'm going to attempt to channel my inner parody stream-of-consciousness Petey Molyneux on this one in order to really appropriately disappoint you
fully...

Here goes:

"This rather quite posh computer game modification to the recent
software title Fallout IV adds an only vaguely-familiar absurdly
overpowered plasma shotgun like thing to I guess what you would describe
as the really quite thematically appropriate cat lady's house in
Diamond City (the Hawthorne Residence in the Upper Stands, for those who
aren't aware that there were little secrets still hidden in the game).

Shooting this monster causes something that I am only allowed, at this
point, before release, to call "a fair bit of death". This is clearly a
first for the industry and, frankly, stands to revolutionize the
industry. You'll see.

Whacking with it (melee to be precise) causes, or rather, leads to, the
deployment of a hunter-killer like drone cat. Unfortunately, cats as we
all know are HIGHLY finicky. Not easy to order around at all. They'll
really have none of it, I think you'll find. If you don't like the idea
of sacrificial felines, well, you can imagine them as deities, or
cavemen, or disembodied hands in the sky, or Heroes. That's really up to
you.
Not our business.

The true extent of said finickiness was surprisingly hard for our very
talented team to implement, but we hope you'll enjoy it - it's state of
the art in this space, and you may not see it anywhere else anytime
soon.

So, yes. The explosive cats. THEY choose who and when to attack.
Not you, silly. Lack of player agency is an emerging concept in this
genre -- and we here tend to play around with it (and you, the player)
in the future.

Those seeker bomber cats I just mentioned can be highly frustrating and
not at all useful. And using them, once in a while, you know, it may
definitively backfire. Kaboom, and all that.

But... That's the draw of good game design, you know. In Fallout 4, you
never know what you are going to get. In this case, you'll get a bit of
barmy fun that'll leave you quite gobsmacked, I reckon.

I am advised that one lucky dosser will, potentially, depending on how
things turn out (but probably not), win a once-in-a-lifetime experience.
They are saying, the bigwigs are - "no riches this time", I'm afraid. "