Squirt is one of the new Scrappin' Dailies of WOD.
Start with Pandaren Mechanical Dragonling Get your Decoy up first, it will negate incoming damage. From there its just Breath spam until hes within about 98 life left. His The Lord of Darkness's Weakness will decrease your damage by 50% so be sure hes in range for Thunderbolt, to edge a little damage off the back row.
When Tyri comes in he's gonna hit hard, so just use the dragonling to soak Call of Darkness and Surge of Light. Keep him in for as long as you can or until light stuns, then swap for the Blighthawk. With Blighthawk in, start with Infected Clawk. I usually only have to use claw for 2 rounds to get him range for Ghostly Bite and hes done.
With Puzzle in play, just pass the round if Blighthawk is stunned from Ghostly Bite. If not, just use claw. Puzzle will start with Coin Toss, then go into dodge, so use Lift-off to let the dodge resolve. After coming down, watch his health. It should only be a matter of clawing him down to within range of a final Ghostly Bite. Rememeber, your damage will be increased with the debuff he puts up on you !