WoWDB

To carry vs this guy, I'll use a double Strider team. I use Eternal Striders, but whatever.  The enemy team is rather trolly, lots of heals, some multi-round evasion.  I try to get the first two out ASAP.

First up is Siren, a Sunflower.  Basically just spam Pump.  Heal after Solar Beam, unless he crits, then just forfeit and restart.

When Toothbreaker comes in, Sneak in a Water Jet before he goes under, Healing Wave, build up a Pump Up, then he'll come up, unleash your pump, then spam Pump.  He sometimes becomes CD locked, if he does and your heal's off CD, go ahead and heal up since you don't have to worry about him going back under or healing again (you'll need the addon Derangement's Pet Battle Cooldowns to tell).

Brood of Mothallus.  His first move is Acidic Goo, 2nd is Burrow.  This is the pet you want to swap your carry in against.  I don't have any hard and fast rules here as to when to swap in, just play it by ear.  If you want to play it safe, though, right after he comes up from Burrow is a good time.

Was able to solo entirely with a Small Frog using Water Jet and Healing Wave on cooldown. 

Pandaren Water Spirit can substitute for the Small Frog.  RNG can force you to use a second pet.