Judging by the last few weeks, Blizzard seems to be running out of ideas, let's help them out! :^D
Clockwork Gnome makes a wish.
All the numerical values on minions get rotated clockwise. E.g. Taz'dingo becomes a 3 mana 5/4, Starving Buzzard becomes a 3 mana 2/5, Grommash becomes a... better make it counter clockwise.
Neptulon's revenge.
At the start of each player's turn, their minions take damage. The amount of damage rises and falls between 1 and 4 as the turns go by.
Don't mess wit' 'da Voodoo Doctah.
Both players start at 1 health, first player to 30 wins. Shuffle 10 or so copies of some card which allows you to discover a healing card into both decks to stop Reno and there you go.
So original that I want to kill myself.
First player to hit 0 health wins.
Let's see you do better.