Sometimes artistic license goes so far with a character that it changes their whole personality.  When introduced, Killer Croc was a strong, yet intelligent guy with a skin condition.  He lived in a swanky home, was smart enough to become king of Gotham's underworld, and was the most credible threat to square off against Batman in a long time.

At some point, he went from looking like this:



to this:



When his humanoid appearance was discarded, so was his intelligence, class, ability to string a complete sentence together, and the know how to rule anything more than the corners of the sewers no one else was interested in.  His appearance changed so much that I doubt most writers even know he's supposed to be just a guy with a weird skin condition and not some weird mutant or science experiment gone horrible wrong.

I'll have to look for some images later, but here are a few of mine:

Any version of the Black Panther with jewellery or other accessories that detract from the simplicity of the classic costume.

Any version of Moondragon without the green Vampirella-style swimsuit.

The Sub-Mariner when he's wearing that vest.

The Forgotten One in that buffalo headgear.

This is the first time I ever saw Ditko draw Batman. As a matter of fact, I don't remember him ever drawing DC's big guns. 

Believe this is Hulk 2099

There's an interview with Giffen in The Krypton Companion in which he argues that whereas most artists think of Superman as a "towering" figure, his Superman is "a squat little guy".  

As out there as the surrounding artwork is, his Superman was actually pretty faithful to Joe Shuster's.    

On Joe Shuster:

"Nobody did him better, and nobody's done him better since... or will do him better.  I was also [inspired by] the Max Fleischer cartoons.  That's exactly where I stop with Superman.  If I were to do a Superman story today, I'd still draw him in that style.  To me, that's Superman: he squints, he's got that jaw with the bull neck, you know, he's a squat little guy.  I'll give him maybe six feet of he's standing up straight.  But five feet, 11 inches, maybe five-foot ten.  He's like the Thing.  Everybody thinks of the Thing as this huge, hulking guy, but if you look at the early FFs, he's shorter than Reed Richards.  So Superman to me has always been that skyscraper-leaping, scrappy guy".

Giffen was also asked what he would have done with Superman if he had revamped him and said that while he'd be faithful to the Lois-Clark-Superman triangle, everything else would be changed ("no Daily Planet").  That's kind of how I feel about his work here - even though Superman looks like Superman, everything around him is so weird and different that I find myself questioning whether I can be certain that is Superman ("Surely this isn't the type of world Superman could exist in").

Kind of reminds me of this (from the Bizarro World installment by Chip Kidd and Tony Millionaire) 

I'd be curious to see more Ditko Batman, also Richard Sala! I thought Giffen's Superman (I had a few) was bringing back the Joe Shuster face which wasn't a terrible idea. I started buying Action regularly when Gil Kane was on it just before that. Joe Kubert did a great Hawkman, but his Superman, while not wrong at all, had a different feel... I'm not sure if he ever warmed up to the character like he could with Batman...

from Justice League of America #200

I've posted this before elsewhere I think but this British hardcover annual from 1969 had some very wrong seeming colouring at the the time... but then later I found out they did have a red and white Iron Man for awhile.