VGFacts

In early screenshots of God of War, Kratos' tattoo was in the shape of the omega symbol when it was seen on his head.



Source:
http://godofwar.wikia.com/wiki/Kratos#Trivia

It's worth noting Kratos went through a good number of redesigns/concepts before settling to the current one.

http://gamingeverything.com/god-of-war-c...s-designs/
http://www.siliconera.com/2011/01/04/god...and-after/