One of the best "go to" pets in early leveling is the White Kitten (or any cat... I happen to like the White Kitten.) They're cheap to purchase (Alliance side) and Beasts are one of the best early choices. Horde side, I would go with a Snake. Other favorites are goodole Cogblade Raptor, the often ig...

For Kromli and Gromli, you can open with Flayer Youngling (1,2,1) and cycle 2,3,1,1,1

Flayer survives Kromli with just a bit of health left. Depending on RNG, you can usually get off at least one blitz... if you're lucky, you can cycle through deflect,kick,and blitz at least twice.