Mulligans
In the last expansion, Galvanizer was a card that made Mecha'thun into a fantastic card. When the new Rastakhan set released a card called Helpless Hatchling, I thought it could be used in a similar way. Gahz'rilla is a card that has a powerful effect but it’s very slow for Hunter to play and also to expensive to give charge Tundra Rhino and damage it to make it stronger.
This combo is used by the effect of Helpless Hatchling, Tundra Rhino and Loose Specimen to make Gahz'rilla powerful. You play Helpless Hatchling and give it Play Dead to trigger abilities. Helpless Hatchling must only be played if you have Loose Specimen, Tundra Rhino or Gahz'rilla in your hand. Play Dead will help reduce one beast in your hand, but not enough. The combo needs a minimum discount of 7 mana to work.
If you have two Play Deadand one Feign Death, you will have a 6 mana discount (when the Hatchlings dies) for 6 mana spent. However, if you also play Baron Rivendare you can make a total of 12 mana discount, (if Baron survives) for 10 mana spent.
When your combo is ready, then you first play Gahz'rilla. Second you play Loose Specimen to damage your Gahz'rillafor 6 damage at best which will make Gahz’rilla having 384 Attack. Then you play Tundra Rhino to give other Beasts Charge. If your opponent have a Taunt, You could probably kill it with Hunter's Mark or Loose Specimen itself.
Maybe Baron Rivendare and Loose Specimen should be replaced with x2 Arcane Shot or x2 On the Hunt.