No-No

A couple of posts have already highlighted the use of moths to kill - the choice of three strong against aquatic attacks helps.

But to clarify, if anyone is having troubles the key points are:
- take Cocoon Strike and something like Moth Dust with a chance of stun
- have a pet with more than 291 speed without the flying buff meaning you'll always go first
- use the stun attack on cd (unless the dam is up)
- since you are faster, you'll always see when he goes under water, use cocoon strike then to avoid the hit
- use your basic attack the rest of the time

Majority of the time, I can kill him just using one moth.

If doing nzoth quest line he phases out so you will need to talk to Zidormi at 79,24 Mogu'shan Palace

Level: 25
Type: Aquatic
Quality: Legendary

Health: 4144
Power: 450
Speed: 291

Abilities:
-Beaver Dam
-Dive
-Tail Slap

Pet battle tips:
-His abilities are strong against undead and elemental pets.
-His abilities are weak against humanoid and magic pets.
-Flying pets are best for this fight.

I was able to beat him with two- level 25 (Rare quality) moths.