The dream is to get the brood buffed up to 6+ attack per dino. This is done with Prince Keleseth and Warsong Wrangler. Play up to 6 of the brood and drop a Tundra Rhino to make them all charge face for 30+ from hand. 

Here's the dream in replay, even after my Warlock opponent played a turn 10 Reno Jackson and turn 11 Twisting Nether, only to die from full health on my turn 11.

Tundra Rhino is the best target for Dire Frenzy to ensure you have extra copies when you're ready to drop a board full of brood. 

Mulligan for Springpaw, Fire Fly, and Dwarven Sharpshooter. Keep Tol'vir Warden if you have a good setup for turns 1 and 2. 

Prince Keleseth has always been great in the early game, so keeping him in mulligan to play right away is still the right choice. Just keep in mind that he can buff a brood of 15 dinos so, if you're close to fulfilling the quest, hold him until after you drop Queen Carnassa.