Infinitesimal

I'd like to add some clarification on this achievement as the information above is misleading.

Got this achievement on live servers on January 20th.

You do indeed need an Infinite Whelpling battle pet. You can catch one in Tanaris, near the entrance to Caverns of time. Only one person needs this pet, and everyone will get credit for the achievement. We did not try making more than one Whelpling spawn and are unsure if it works or not, but you only need the one anyways. Pray for Elisande LFR's.

Anyways, the commenters above me stated that when the boss casts Time Stop (her pushes into P2 and P3) it transforms the Whelpling, but this isn't the case.

Throughout the fight the boss will be summoning Elemental adds. The Expediant Elemental drops a large pink bubble when killed that increases your time flow, and the Recursive Elemental drops a large blue bubble which does the opposite. You need to overlap both bubbles by killing the pink add on top of the stationary blue add and then pull your Infinite Whelpling through these bubbles and hold it inside for about 5 seconds and it will grow up into a teenager drake. Once you've got this spawned it does a frontal cone breath attack which does virtually no damage. You can kill it and once it's dead kill the boss.

FrostyShot#1667 if you have any questions.

Easy Solo for Level 120 Battle for Azeroth, and beyond...

1. Normal Difficulty.

2. Take out your Infinite Whelpling Battle Pet. Mine was Level 14, so I know that it doesn't have to be max level to get the achievement.

3. Attack Elisande, but don't kill her yet.

4. Now just a few seconds into the fight (maybe a dozen or so), some larger elementals will spawn. Both of these must be killed close together.

5. Once they are killed, drag your Infinite Whelpling through the puddles created, which should overlap.

6. The Infinite Whelpling has turned into an Infinite Drakeling and has betrayed you for reasons unknown...

7. Kill the Infinite Drakeling.

8. Kill Elisande.

9. ?

10. Profit. Achievement Completed.

Okay so just did the achievement myself.

What you have to do is have the 2 elemental adds die ontop of each other so the bubbles clash, once done kite your whelping into it and it will turn into a infinite drakeling instantly. Has 50mill hp and is easily killed.

Screenshots;

Spawning the dragon; http://i.imgur.com/NiZ63pc.jpg
Getting the achievement; http://i.imgur.com/kuEP0mw.jpg

Also pet level does not matter. We did it with a lvl 14 one.

Another side note; you only need 1 person to do this. We had 10 people or so with pets out then run through the bubble. Rip raid.