the more often it attacks and the more often it crits the more it seems to flank in my experience. I mostly run the Raven pet, I place sign of wild rage on it and I use the rage stickpin. I get a lot of flank responses that way.
and there are 3 ways to spend the flank, staff-strike for a quick melee hit that does more damage, staff-sweep that gives u a little power over time, or the wizard's fire heal.
[COLOR="#3366ff"]Melrok (R10 Guard) Morkel (R12 Hunter) Merlok (R8 LM) Shadowheart (R8 Burg)[/color]
[color="#cc3333"]Grimnaw (R11 Warg) Grimweaver (R11 Spdr) Grimacroncheese (R9 BA)
Rageagainsthelootbox (R8 Defiler) Cheezeypoof (R9 Reaver)[/color]