Acid falls on a pedestal, move off of it when that occurs.
Commonly referred to as "Lord Bob"
Does not drop a chest immediately on death. After killing him you will have approximately 20 minutes to progress through the remainder of the Forgotten Pools to Halls of Remembrance. Success will reveal a special chest containing Lord Bob's loot; failure will result in him resetting back in the upper portion of the zone. Each time he resets he may be killed again for another chance to complete the rest of the zone and claim his loot.