Just a short clip of us completing the "Gotta Go" achievement, where you have to kill Anub'Arak in Heroic Azjol-Nerub in under 2 minutes.
There used to be an easy way to complete this by stacking classes that could increase his cast time, and get his Pound cast down to 9 seconds. This was however hot fixed, and it is a bit harder now, but still doable as this video will show.
Tactic we use is to stop at ~77% and then wait for a Pound and then go all out. You have to get him to below 50% before he submerges (or very close to it so that dots get him below 50% under ground). If you manage to do this he skips one submerge phase and you save a lot of time. Same thing at 25%. We stop at 27%, wait for Pound and then go all out, he has to die at this point or it's over..