You can perform an easter egg on Castlevania: Lords of Shadows (xbox 360 version) by performing the konami code at the Title Screen (when the title screen says "Press Start").
"The Konami Code, known in Japan as the Konami Command (コナミコマンド, Konami Komando ), is a cheat code that appears in many Konami video games, although the code also appears in some non-Konami games. "
<- At the title screen
Once you've entered the konami code, you will hear a short ringing sound. You will obtain a weapon entitled "Konami Man" upon the slaying of your first creature in the game.