In Mortal Kombat (aka Mortal Kombat 9, 2011 version) for the PS3, Kratos has an alternate costume but it can’t be found in the Krypt like the rest.
To unlock Kratos’ alternate outfit, beat Arcade Mode with him. After that, go to the Nekropolis in the Extras menu and click in Kratos’ statue and alternate outfit will unlock.
(Please verify in comments since i’m using the Xbox 360 version)