Tests done on stormwind dummy. No armor.
Cobra Shot no Pets: 48 588
Cobra Shot Dire Beast: 52 477 (8% increase)
Cobra Shot with Pet + Hati: 56 364 (16% increase)
Cobra Shot with Pet + Hati, Dire Beast: 60 250 (24% increase)
Previous tests showed that Hati didn't contribute to Way of the Cobra, but now it appears that it does.