Because I have been working on something for my Mystamyr campaign, I came across stats which answered the question of what happened when the player characters killed the Ettin “hero” from Moonspike Tower, Torgahn. In short, he became a Zombie Ettin and consequently rampaged around the swamps until the party put him down (again).
Torgahn was a 2.75 metre (9 foot) tall two-headed giant. He was slain by Glar the Hammer and his body was dumped in the marsh to rot by the Moonspike Goblins. Following events in Anminster, the power of the Lich Kelamaz raised the Ettin’s body and now he exists as a powerful zombie, prowling the edges of Lake Mirrormere.
Hopefully this will amuse someone out there.