During the level "Dark Woods of the Serpent", you may encounter a secret area obtaining a very aggressive and deadly white rabbit. Lo Wang will comment on him saying "that's no ordinary rabbit". The rabbit is protecting a cave with the Holy Grail that you can blow up. This is a reference to the 1975 film "Monty Python and the Holy Grail".
Contributed by shaggytoad
Behind a secret wall which can be destroyed by blowing up some nearby TNT barrels in "Dark Woods of the Serpent," You can find Lara Croft from the Tomb Raider series chained up in a cell. When you approach her, Lo Wang will comment, "She's raided her last tomb." Inside her cell there is also a fortune cookie.
Contributed by gamemaster1991