I made these mods from scratch as the various mods from Plutonium and UGX Mods that preceded them (which made the main Easter eggs in Call of Duty: Black Ops - Zombies solo-able) either don't work as they ought to or the files are lost due to the download links being dead.

The following patches are compiled .ff files from the source files and work with the vanilla version of the game. These fast files only contain modified GSC files that control the logic for the maps, not the maps themselves. You'll need to purchase the DLC for these mods to work.

All achievements corresponding to the maps are available to unlock as normal via completing the Easter eggs and completing various challenges on the maps.

Note: All players in the lobby need to have the corresponding patched .ff files installed in order for the maps to load if you're not playing the maps in solo mode. It's advised for everyone to play this mod in the English language. Using cheats may break the Easter eggs. Only the Steam version (on Windows) of the game is supported at this time, although it wouldn't be too difficult to get this to work on the Plutonium mod or any other version.

Known Issues: The game partially removes Mule Kick when using custom patch files, the perk won't work properly so don't get it and the Easter egg steps in Shangri-La can be flaky (but work nonetheless). Poor networking conditions may cause your game to crash or end the session in coop (but not in solo).
I give full permission for these mods to be forked and published elsewhere if improvements are needed for functionality and compatibility of these mods.
Please comment if you encounter an issue or have a question.