I know some people have been itching to fight these & just wanted to mention that so far information posted on the BG forums indicate that these new Beastman Kings are likely only linked to Beseiged.
Of all the LS which have killed any of them they received no experience or any items from them. And one person noted that after spending a long time getting to Medusa they had seen it was up then the Undead won in besieged & took the AC & Medusa was no longer up.
It's possible they don't have loot tables assigned yet or that they are only put there to be killed to weaken the besieged forces.
Thought I'd share.
Of all the LS which have killed any of them they received no experience or any items from them. And one person noted that after spending a long time getting to Medusa they had seen it was up then the Undead won in besieged & took the AC & Medusa was no longer up.
It's possible they don't have loot tables assigned yet or that they are only put there to be killed to weaken the besieged forces.
Thought I'd share.