Zanzibar Easter eggs

In the Halo 2 multiplayer level, Zanzibar, there is a sign that says, "Danger, No Swimming" and has a picture of a shark on it. On certain dates the sign will change.

Signs

 * On 01/01 the sign reads, "Baby Shark Petting", and has a picture of a little kid petting a smiling shark.
 * On July 7th, the "No Swimming" sign has a poster taped over it with a picture of a decapitated dog's head with what looks to be rabbit ears instead of dog ears, it reads "Are you finding Ling-Ling head?" This is a reference to an ongoing Bungie joke about needing the head to rule the world, which itself references the Missing Dog Head image.
 * On 10/31, it is a warning sign reads, "Danger, Carnage Zone" and shows a guy getting disemboweled (the disemboweled person is also the Halo 3 Splatter Medal symbol).
 * On 12/25, it reads, "Danger, This Soffish, DO NOT EAT!" and shows a Sofish (toy) fish on a dinner plate.

Opening the Gate
When a player opens the gate, the screen where the switch is activated has a "Blue-Screen" error (that occurs on the Microsoft Windows OS), commonly referred to as the Blue Screen of Death. A total FU exception has occurred at your location. All system functionality will be terminated. *Press any key to power cycle the system. If system does not restart; scream at top of lungs and pound on keypad. *If you need to talk to a programmer press any other key

Press any key to continue_

Find LingLing's head
If the base's gate hasn't been opened, you can see faint outlines of a dog's head and a grunt's head on the big metal base in the bottom middle of the gate. The inside-facing image looks like a dog's head, and the outer side is a grunt's head, with respirator. This is much easier to see if you throw a plasma grenade at it.

Trivia

 * It is possible to see the signs when it is not the correct date. First put the date of one of the signs in the Xbox or PC options and then play Halo 2 and go to Zanzibar. You will see the sign of which ever one's date you put on the Xbox or PC.
 * The sign on October 31st is the same as the splatter medal in Halo 3.