Hearthpwn

So I'm assuming it's a quest? The Caverns Below seems to fit fairly well.

Yup, that's it, The Caverns Below.

Oh wow, wasn't expecting to get it right. I guess I'll have to come up with something in the morning.

Looks like I forgot... here's one I made real quick, might be tougher than my previous riddles.

Many call me weak

claiming I am only a baby

but in reality they seek

above all else, my safety

sometimes victory goes to the meek.

Addled Grizzly?

Quote from PinkiePieYay >>

Addled Grizzly?

Quote from Derkos15 >>

Murloc Tinyfin?

 

Sherazin, Corpse Flower?

C'Thun

I'll take a stab with the ancient one/blood of the ancient one.

Both are eldritch abominations, perfect to give you nightmares.  The ancient one is 'awakened' by summoning 2 bloods.  9/9 and 30/30 are both durable statlines, with good damage.

As far as wired goes, I was thinking maybe a mech, but it could also just be to make the rhyme-scheme work.

Ysera?

A lot of people are afraid of me while they’re sleepy, - This may be understood as simply a card related to dreaming, maybe a ghost or a demon to scare people at night or in their dreams or an assasin that waits to kill his target. It could also mean a card which can be missplayed, since it's hard to play when you are sleepy.

But it is when I wake up, that it gets creepy. - This card waking up clearly suggests a minion. Waking up can be understood as: literal waking up (like C'Thun, but sadly this card is not an answer to riddle), getting played (when in hand the minion sleeps as it doesn't take active part in game) or getting enraged (minion sleeps when it is not enraged). Getting creepy could support my idea about it being ghost, demon or assasin, since you don't really feel that much happy knowing they are around you somewhere. It could also be translated to strong, threatening, creating havoc, since creepy is a synonym for scary, a word which is commonly used about powerful minions.

Hard to take down and deadly when that’s required, - The first part is pretty straightforward. Deadly when it's required means it has some offensive abilities, but it is not limited to them.

now just solve this riddle, I admit, it’s pretty wired. - The only help from this line is the word "wired". It could simply mean that this riddle is hard and not pointing us to anything, but it could also point out to being a mech or something with a rope, string or even tentacle. Could also mean hard in terms of using, which supports my idea of missplaying with it.

The cards this points out to (at least in my humble opinion):
Grommash Hellscream (lots of health, threatening because of burst damage and offensive; missplay: not enrageing it before attacking?),
Krul the Unshackled (lots of health, scary looking and possible of creating massive boards; missplay: not having a deck duplicate free),
Scaled Nightmare (nightmare in title, lots of health and if left on the board it can be offensive; missplay: ???),
Ravenholdt Assassin (assasin, stealthed, high attack; missplay: ???),
Ogre Ninja (ninja, stealthed, deadly when it wants to be in terms of his effect; missplay: not clearing up "bad" minions),
Lotus Assassin (assasin resolving around stealth; missplay: too many trades that make him vulnerable),
Fel Reaver (mech, very big and threatening, scary looking?; missplay: not forseeing how many cards can your opponent play),
Dreadsteed (demon, hard to get rid of, wired - combined with Mayor Noggenfogger makes things complicated; missplay: not playing around silence???),
Am'gam Rager (overall ghost, lots of health, could be combined with Inner Fire or Crazed Alchemist for offensive abilities; missplay: ???),
Wailing Soul (scary looking, capable of silencing frozen minions; missplay: silencing useful minions),
Patient Assassin (assasin, stealthed, possible instant kill because of poison; missplay: not playing around AoE),
Kel'Thuzad (threatening board, can hide behind constantly resurrected taunts; missplay: just picking the wrong time to play),
Ragnaros the Firelord (big, threatening, hard to kill, can be offensive; missplay: not clearing up "bad" minions),
Mal'Ganis (threatening board, offensive as well as defensive capabilities, demon; missplay: ???).

If the answer is not one of those, then .

Haunted Creeper maybe?

Silithid Swarmer would make sense.

A lot of people are afraid of me while they're sleepy- It's a huge tempo loss for you when you play this and cannot attack (when you are sleepy)

But it is when I wake up, that it gets creepy-  Just look at the art and how creepy it is.

Hard to take down and deadly when required- It has higher stats than most other minions of the same cost and when you attack it can be deadly to your opponent or their minions.

Now just solve this riddle, I admit, it's pretty wired- Two things: one, he is related to the Old Gods which have tentacles all throughout Azeroth, making them wired to the Earth. Two: he is very hard to use especially in arena.

Quote from Treecer >>

Alright, this one should be pretty straightforward:

 

Underneath the earth

Many riches lie

But I planted something

That will make you die

 

Iron Juggernaut

Quote from Maukiepaukie >>

Iron Juggernaut

You see stench, filth and gore

But I consist of so much more

Hurt me and face my wrath

Which might consist of rather confusing aftermath

Sounds a lot like Rotface

Ah damn, felt like it was a bit too easy haha.

You got it fair and square. You're up.