eternal strider 2,2,2, emperor crab 2,2,2 and golden civet 2,1,2
cleansing rain, poison spit, pump, pump, poison spit, bring in crab; whirlpool, healing wave, surge til whirlpool is off cd, reapply whirlpool (crab dies) bring in civet dive, screech and gnaw X 2. Deathscreech dies.
A simple 2-Pet Strategy....if you have 2 Gulp Froglets. :P
1st Gulp Froglet = Mudslide > Water Jet > Water Jet > Corpse Explosion (use Corpse Explosion when your pet has less than 500hp)
2nd Gulp Froglet = Toxic Skin > Swarm...boss dies last round of Swarm. : )
*(Feel free to have 3rd pet be Moonshell Crab for an Arcane Slash, just in case you have terrible luck/rng)
I managed on the first try with Moonshell Crab (1,2,2), Emerald Turtle (1,2,2) and Ghostshell Crab (2,2,1). Amplify Magic first, then Moon Tears, then Arcane Slash until Moonshell Crab died; then just Emerald Bite with the turtle. I didn't need the second crab at all. My Moonshell is P/P and the turtle is H/H, and I was lucky this time and didn't get any crits from Deathscreech. (The turn in which it uses Greater Apocalypse seems a bit random too, which can affect strategies.)