Listen here.

I know it sounds strange, but this deck might be really good. Maybe.

Remember your old pal Dreadsteed? Well we've got a better version of it, Cruel Dinomancer. It was not really playable in the past, as the discard mechanic was something too random to be reliable... until now! (Thanks Expired Merchant)

Game plan

Start the game like a regular Handlock. Tap tap tap until you can play your Mountain Giant and Twilight Drake. The ONLY exception is if you are playing against aggro and need the help of a Doomsayer, or if you have Expired Merchant + Cruel Dinomancer in hand, and no other minions more expensive than him.

As you go through the game, you will be able to pull out that combo and have your 5/5 monster on the board. Now, it's time to multiply it! In addition to Expired Merchant, 2 other cards can generate more dinos, Baron Rivendare and Spiritsinger Umbra.

The first one will be able to generate those 1 by 1 each time you kill one of them, using EVIL Genius or Shadowflame for exemple.

The second one, oh god, kill one of them and they will be spreading like plague.

The idea is the same as for the old version, trade a lot with your waves of minions, and send them closer to death each time they have no minion to play. Just be careful about aoe that doesn't trigger deathrattles (I'm looking at you, Priest and Shaman!) and try to keep a dino in hand to repopulate your board.

Oh no it's not perfect!

Yeah, I know, Genn Greymane and Mountain Giant can be discarded by Expired Merchant.

It should not happen with the giants, as their cost will be greatly reduced, due to the fact that you are able to draw a lot, but might happen with Genn. Now you will be extra unlucky if you draw it early. However, I still think it's an important part of the deck, because it allows you to draw really fast to setup the combo.

We could play cards like Bloodreaver Gul'dan and N'Zoth, the Corruptor to increase our late game a lot, but it would mean having to play them before discarding a dino, which will be difficult in most games.

Conclusion

Enjoy!