Madam Viciosa

This master tamer is new in 7.2 and is active through a world quest. See Lazey's comment for more detail, I also recommend watching the linked video to find Madame Viciosa, since her location on the map is currently incorrect (might be fixed when 7.2 goes live).

A possible strategy to beat her and carry a pet below, as well as on Xu-Fu's guides:

1. 
   
2. Level 10+ pet
3. 
   
4. Unborn Val'kyr (1 2 1)
5. 
   
6. Mechanical Pandaren Dragonling (1 2 2)
7. 
   

Strategy:
Pass with your level pet, it's swapped out.
Curse of Doom, Shadow Slash, Shadow Slash, Haunt
Bring in your Mechanical Pandaren Dragonling
Decoy, Breath until the first two enemy pets are dead
When Seduction enters: Thunderbolt, Breath until MPD is down, then Shadow Slash with your Val'kyr to the end. Win!

What I want to know is, is it pronounced VisO'sa, or VisioSA'? **gives feather a flick**

Leveling Pet: must have >800 health (50% more health required if dragonkin or flying); I used level 15 roach with ~1000 health
[npc=63001] (2,2,1) - breed: health & speed (alternate pets with the same moves found here)
[npc=62621] (2,2,1) - breed: guardian (alternate pets with the same moves found here)

Ensure your pets are in the slot positions as listed above.
Regarding the leveling pet: if you take crit damage in round 1, you will need to watch your leveling pet when fighting Rover to ensure the AOE does not kill it. If your leveling pet dies to round 1 crit plus Rover AOE, simply restart the fight and try again - or grab a leveling pet with more health.

vs. [npc=117982]

• Start with leveling pet
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• Attack or pass - either way this pet is swapped for your next slot ([npc=63001])
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• [pet-ability=310]
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• [pet-ability=449] x3
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• [pet-ability=564] ([pet-ability=466] misses)
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• [pet-ability=310]
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• [pet-ability=564] > [pet-ability=449] until opponent dies

vs. [npc=117983]

• Swap to [npc=62621]
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• [pet-ability=172]
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• [pet-ability=179]
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• [pet-ability=501] until opponent dies

vs. [npc=117985]

• swap to [npc=63001]
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• [pet-ability=310]
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• [pet-ability=449] x2 (critters are immune to stun, so [pet-ability=772] does nothing)
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• [pet-ability=564] ([pet-ability=218] misses)
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• [pet-ability=310]
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• [pet-ability=564] > [pet-ability=449] until opponent dies
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• If [npc=63001] dies before [npc=117985], then bring [npc=62621] back in
• 
  
• If [pet-ability=172] weather effect is still up, use [pet-ability=179], otherwise, use [pet-ability=172]
• 
  
• [pet-ability=179] > [pet-ability=501] until opponent dies

Both of my pets were level 25 & rare quality. I used the listed breeds and have not tested using other ones. Based on my testing of the fight and the available breeds for the pets used, I don't think breed will make a difference for this fight. Both pets I used are easily capturable at high levels, so hopefully this strat is helpful.