He seemed to only stay spawned for 4.5 minutes or so:
*Spawn
[Mon May 26 09:46:12 2014] Ogog says 'I Ogog, har har.'
[Mon May 26 09:46:12 2014] Torgon Blademaster says 'Farewell.'
Moments later, he despawned with the same dialogue of when he spawned the first time.
*Despawn
[Mon May 26 09:50:47 2014] Ogog says 'I Ogog, har har.'