In the beginning I thought that the game just shrunk the character model except the heads, but then I saw that some of the Puzzle Fighters outfits are different. Shujinko's and Noob's outfits are different in Puzzle Kombat than either of their two costumes.
Also, Smoke's puzzle fighter uses his alt costume while most everyone else uses their main costume... except for Jade.

How would I do this with Action Replay?

Who is Ghost? Do you mean Smoke?

Ghost is the Spirit of Liu Kang that trains you in Earthrealm. At the White Lotus place.

No, he measn the transparent Lui Kang that you train with. He's called Ghost... just like the Scorpion dude is called Monster.
I was thinking about this.... remember a long time ago they had some guy... and he was like, "Yeah, so, Scorpions alt. is like a skeleton head with bones coming out of his side..." Well, that to me sounds exactly like Monster, if you ask me.
I'm really starting to think that Monster will eventually be a secret character, maybe even a Scorpion Alt - but based on his name, Monster, being on the puzzle screen, I'm sure he'll be his own character.
As for Onaga and shit... that blows me away.
WHY DOESN'T ANYONE SAY HOW TO DO THESE CODES? That confuses me.
I have Action Replay. Dammit.

Just added Ghost pics. He looks a bit different than the Konquest Ghost. A lot more red in him, not just clear-blue this time.
http://www.elranzer.com/mkd/

Sorry ActingArtist, the codes I used were for CodeBreaker. I use to us AR MAX myself for a while but quickly converted to Codebreaker, since the guys who run AR MAX are so slow releasing new codes.

Yo, someone figure out how to use monster without a hack!!! oh and i think that raidens alt would also be unlockable

How?

This stuff is hot; I couldn't believe it when I sore Monster wins! lol
This is great. But I think that maybe these fighters (Ghost, Monster and so on) are the last thing you can unlock in the game.
Like in MK:AD with Blaze and Mokap. I think you got to complete Konquest, unlock everything in the Krypt and complete Arcade mode with every fighter. Then you get these hidden ones.
I can't see Ed Boon spending the time putting them character's in the game if you can't really unlock 'em. I mean, it was a stroke of luck you came across 'em in the first place.
BUT..........
Maybe we weren’t meant to unlock 'em at all.
Think back to when 'WWE Smackdown : Here Comes The Pain' came out.
I was well pissed off to find out that Hulk Hogan and the Ultimate Warrior wasn't in the game but after some time I found out that they were in the game but you need a codebreaker to use 'em.
It turned out that they were meant to be playable characters but at the last minute they decided to take 'em out over copyright bullshit. (I think)
Who knows, maybe Ed Boon pulled the plug on these character's at the last second cuz he changed his mind.
I don't know, it's just what I think. But great find man, keep it up.

how does the codebreaker work?, when you get the "secret" characters how do you select them?

Regarding SithAngels comment, I've beaten it with every character and unlocked all the koffins (except for maybe WQ). I haven't seen anything like this.

If people can't find any way to unlock them then it's like 'Smackdown'.... They wasn't mean't to be playable!

How about you go play a bit more letter scrabble with the Kombat Kodex and see if you finally decipher a secret backwards message to unlocking Shang Tsung's little beanie hat from MKII.

To souledge: ?

WOW!!! this is cool!!!! keeping hope alive for lots of secret stuff!!! :))
Also... remember when we first really saw havik, it was in puzzle...
So... what do I buy this Codebraker and where do I find the codes???

Great find! I knew those guys had to be in there otherwise why would midway show them in videos and not include them. Now we just need to know how to unlock them.

I'm thinking it may be like kitana in MK4... when u could only get her with gameshark... cause boon did not want her there but the others did...

When you play as monster in the puzzle kombat, does he have his own square or is he just anyone u pick?

He is using the CodeBreaker game to unlock them. He is not finding out how to unlock them. The screen shots are of him playing as that character. I am sure that you have to do something to release that character. What that is, no one knows, yet.

Very interesting. I think all of these can be unlocked, some how.
REASON
I WANT ALL PEOPLE TO READ THIS!!
here is a direct quote from the ign review
With nearly 700 secrets in all, it's easily the biggest MK ever in terms of single-player unlockables.
Almost 7 hundred unlockables. The krypt goes to TT. T is the 20th letter. 20x20=400 Our krypt only has 400 coffins, which includes all the secrets known so far. The DA krypt goes to ZZ. ZZ=26x26=676 witch is almost 700. I think our krypt is bigger than we think.
As far as koffin WQ goes, I think that it is meant as a hint to the bigger krypt.

good point

just confused, is anyone going to say how to play as these people when using the codebreaker, I see the pics, I hear about it, but I don't know how I myself can do it

so do they have a code breaker for xbox or anything like it cause i got a xbox

I am pretty sure xbox has a codebreaker