Hearthpwn

A powerful body for a mill druid. Card text is a heavy drawback which can be used as an advantage only in that archetype (which almost doesn't exist now). High health and attack could help it get rid of some low mana minions while providing constant card draw for the opponent, leading to quicker fatigue.

Edit 1: Changed wording to make it more clear.

Flavor Text: After the kitchen incident she decided to change jobs.

Low cost, pretty strong. However, it will kill your minions. Good in a Deathrattle deck, but in any other deck it may be good for early pressure, but you won't be able to summon minions because they will get killed. Also, you take quite a bit of damage when the card dies.

Flavor Text:He tries making the wrestling team all that happens is he gets pinnned down, druid sad.

A nice body, good cost and gets rid of a minion! Perhaps you ran into a spot where you couldn't get lethal because of a taunt, no problem - Straggling Druid. Of course this not all you need you get 2 dmg dealt, so he might erm, kill you

My entry:

I have no idea if there's anything similar, I just skipped to here to upload my card. Hope you guys enjoy!

Flavor text: Lorewalker Cho has learned a new trick.

Edit: Made it a rogue class card.

Here is my submission!

"You probably don't want to click this.."

Was trying to balance it similar to Doomguard, but a little more OP for the mana due to its potential destructiveness.

Observer Grind , it's real.

For Warriors, obviously. A big tempo swing when you have a lot of armors. Though if you have too much armor, you don't want to use it because it will get rid all of them. Combined with Molten Giant, this should open a possibility of Giant Warrior. 

Ramp alternative, but attacking with it locks you on 3 mana crystals. Excellent for taunting, though.

famous weapon in wow. Same cost, attack and health with Ashbringer given by Tirion Fordring. But it keeps shielded minor and recruit away...

It is a 6/6 minion with a drawback (silence)