(again, sorry no pics or videos as I no longer have a WC account, sorry)
To get this pet you need a high-level character and a lvl10-14 toon.
Take both to darkshore to the ruins where the trolls are, south of the shatterspear warcamp.
Form a group between the two and set loot to group.
Collect cat figurines littered about the place and use your high lvl character to kill any trolls that
get in your way. Something like 5% produce a ghost sabre. Kill the ghost sabre. Then have
your low-lvl character loot the dead cat. They have to be nearby in order to be able to loot the
dead ghost sabre.
(It is a little awkward to do this with trolls lurking everywhere whom your low lvl character won't
be a match for, so using a sympathetic guildie to act as the high lvl character would make
this a lot easier. )
This will give your low lvl character a glowing cat figurine which will allow them to summon
a lvl20 ghost sabre for 10 min. This works in 10-14 bg's (tested).
When using the cat in the bg, it is very important that you stay alive (the cat vanishes when
you die) and that you stay close to the cat (it vanishes when you move too far away).
This is not that easy in a low-lvl bg where you can easily get one-shotted with poor gear, so
you probably want to twink out your low-lvl character. If you aren't a healer, you probably want
to enlist one to protect you.
If you are a hunter you might want to use a cat as your main pet here so the enemy will be
confused about which pet to attack. Get your pet to attack before unleashing the ghost sabre.
A rogue is a good choice here as you can stay close to the ghost sabre without unstealthing,
just watch out for aoe.
The ghost sabre is very strong and will kill anything one-on-one, even a twink. Aside from its high level
the stealth adds considerable surprise to its attack. However, it is not indestructible and the
other team can kill it if they work together. For that reason you might want to save it for an
enemy without too many looms or twinks.
It is work to get this cat, but it is enormous fun to deploy it, a pretty much essential experience
for a pvp exploiter.
I'm not even sure this is actually an exploit, but it doesn't seem very likely to me that Blizzard
envisaged this cat being used in low lvl bg's as, done right, it will rip through the entire enemy
team.