TEEN MODE, or more appropriately Chinese censorship mode.

[Devalut]

Edit:
Testing maps in editor prompts the game in teen mode, turn off in file>preferences>testmap tab

EDIT:
Below changes are just results from Teen mode or "Reduced Violence"
Blizzard in their wisdom have replaced or outright deleted numerious resources containing skulls in the classic version of warcraft 3.


Here's a skeleton model, this includes giant & dark minion variations:

Abomination with GREEN blood

ICONS (in order left to right)
Raise dead, Frost Armor, Sacrificial Skull, Claws of attack.

This one is harder to understand but, various units have blood effects when they die, here's a reduced list of spawned effects on patch 1.31.1:

 

[TriggerHappy]

Is this the case even without "Teen mode" enabled in the settings?

 

[Devalut]

Thanks @TriggerHappy I was ready to go fly off the handle there.

AH, there we go, it's all back.
For those of you unaware of this option go to file>preferences:

 

[HerrDave]

Let's not forget about the edited or outright removed voice lines, due to the lovely political minds at Acti-Blizzard.

 

[Devalut]

What's frustrating is that's not part of teen mode, they are just gone.
I don't care if you interpret the voice lines as "problematic" they were made 18 years ago you watery bints.

 

[deepstrasz]

watery bints

Forgot one word

 

[Devalut]

Your's comes up as a dead link

 

[deepstrasz]

Your's comes up as a dead link

Weird. Maybe it's restricted in le Canada.

 

[Devalut]

That's maple syrup land to you bucko.