Everyone is always saying that the panthers can't be tanked. So I made a video of it to show you that they can. I've offtanked panthers many times in 1.11, and always keep 90%+ on me.
http://files.filefront.com/Giller_tanking_panthers_June_2/;5126388;;/fileinfo.html (sorry about the size)
There are 2 tricks to keeping agro on the panthers.
1-The marked person must stay as far from the panthers' spawn point as possible. With the way LaG does it, that means right ontop of the gong.
2-The off-tanks hit+sunder/revenge each panther as it appears. Once they have several panthers on them and extra rage building up, they start to use demoralizing shout (aoe attk pwr debuff) with the extra rage. Eventually, when they have about 10 panthers, they can just span nothing but demoralizing shout every second and that will catch new spawns as well as keep the old ones.
If you put the caster pack on the opposite end of the room from the gong, the offtanks stand right at the opening of the cages instead of at the spawn point. The panthers technically can walk through the fence, but they won't do it until after they have walked to a scripted point by the opening or get agro on the off-tank.
Stoneskin totems also help a lot. With a constant stoneskin totem up, a single healer can keep an offtanking warrior up through the entire fight. This leaves the mages and warlocks with thousands of mana to use on boss dps and healers with plenty of mana left to heal the main tank and damage from the occasional panthers that get through, usually just at the beginning.
