Hearthpwn

Basically, you name a requirement for a card, the next guy makes a card that fulfills those requirements. Try not to make the requirements too specific though, a good guideline would be to ask for something with no more than 4 of the following:

1. Card Type (Weapon, Minion or Spell),
2. Class,
3. Tribe,
4. Statline/Mana cost,
5. Specific synergies (i.e. a card that works with Onyxia, etc.)/General synergies (i.e. supports Pirates, etc.),
6. Or has Battlecry/Deathrattle/Inspire/whatever other Keyword.

Like, say someone wanted a 0 Mana 12/12, then I'd make

Start with 5 Mana, 2/8

Stats for the cost are better than those of an Boulderfist ogre. So this one, "older brother" of ogres a bit bigger and a bit reckless. Not always a bad thing for a Warrior. 

Next one: 2/5 for 4 mana

Tower Golem without background.

Next: 9 Mana 6/10

for example

next: 3 Mana 3/5

So I posted first and got ignored. Neat-o

Here, take both. Next is 8 Mana 1/2

That's a tricky one, but I think this is decent.

Next up, 5 mana 6/3.

3 mana 4/6

7 mana 4/8

Angel that will be awesome if the meta slows down.

8 Mana 8/8

9 mana 10/6

Next: 1 Mana, 2/2

Presenting the Valiant Defender.

Is it a power creep on Mogu'shan Warden? Yes. But it's a class-specific card, and on your turn it's exactly the same.

Next Up: 10-mana 8/14.

I'm not really sure about this one, but here it is:

I'd imagine this would be pretty good in Mech decks, and 7/2 stats for a 4-drop are pretty great if it has Immune.

Next Up: 3-mana 0/4.

NEXT: 5 mana 0/0

Oh, that's just evil.

But I think this works, and it has the potential to be crazy good. Note, it will round DOWN (at 5 Health left it gains 2 Health). Hopefully I didn't mess up my Hearthstone science.

This thread is fun :D

Next Up: Two can play at that game. 3-mana 12/0.

Quote from BambamCZ >>

Next: 7 mana 4/15

Thats superop xD but here it doenst matter.

4 mana 2/2

arthas comes with

next: 40 mana 20/20

I feel like that's a little OP -- it has the potential to be an 11/2 for 3 mana if there's another minion. Maybe -3/+1? So if there's three other minions then it's a 3/3 with Taunt, if there's two other minions it's a 6/2 with taunt, etc.

Anyway! Considering you asked for 15 Health, I figured I'd do a replace-your-hero-with minion. Here he is.

Next Up: 8-mana 7/7.