Infinite Corruptor

Infinite Corruptor is a boss located deep within Stratholme. He is found corrupting a bronze dragonspawn during the Culling of Stratholme, leaving upon success. He'll only drop Reins of the Bronze Drake besides the badges. This is a guaranteed drop.

Players seeking to battle him only have 25 minutes from the first Scourge wave to kill him; merely engaging him does not stop the timer. He is located in the Market Row which is located just past the gate leading to the Mal'Ganis encounter. He's at the far end of the left side of the junction past the gate, while Mal'Ganis is on the right.

He is only present in heroic mode.

Strategies
For all intents and purposes, the Infinite Corruptor is a tank and spank boss.

Getting to him within the time constraints will require a fast clear. In the first few months after the release of World of Warcraft: Wrath of the Lich King, this was a very difficult feat, though reaching the Infinite Corruptor is now considered to be automatic, with better runs reaching him with 10 minutes or more left on the timer.

The most vital strategy is to be aggressive in going after the waves on the first and third legs of the instance. This is especially true on the third leg, as several of the elites can be picked up at the same time, and waiting for Arthas to engage the mobs will slow the group down considerably.

Quotes
Aggro:

yell

Departure:

yell

Death:

yell

Lore Implications
The presence of this npc in the Culling of Stratholme, as well as the activity he is undertaking, would seem to suggest that the Infinite Dragonflight is in fact made up of Bronze Dragons who have been subverted.

Videos
This video covers all Heroic-only bosses - skip to 5:10 for Infinite Corruptor.