IWHBYD skull (Halo 3)
From Halopedia, the Halo wiki
In Halo 3, the IWHBYD (I Would Have Been Your Daddy) Skull is located on the level The Covenant (Level). To get this skull, you must be on difficulty level Normal, Heroic, or Legendary.
The name of the skull is based on a statement uttered by Sergeant Johnson in the first Halo: "I would have been your daddy, but a dog beat me over the fence!" It is also the name of the first chapter of the campaign level Assault on the Control Room in Halo: Combat Evolved.
In order to get the IWHBYD skull, you must complete the entire mission until you reach the final battle scene, where the Prophet of Truth is planning on lighting all seven rings. Once you reach the bridge, battle your way across with the Arbiter and Flood, neutralize all Covenant, watch/skip the cinematic, and kill all the flood (this is optional, but makes the procedure much easier). Once the bridge is devoid of enemies, you will have to literally jump through the 7 rings in a complex order. Once you have completed this, the IWHBYD skull will appear at the beginning of the light bridge leading to Truth's podium.
Each number corresponds to the ring you must jump through. The ring at the elevator is 1. The ring next to Truth is 7. The ring with red on it is 4.
Sequence order: 4,6,5,4,5,3,4
Once you have completed the sequence, the skull will appear at the beginning of the light bridge leading to Truth's podium. If you are not sure you got it then look at the rings when you complete the sequence, they will be blinking. The Halo theme will play as you get the skull. You must then finish the level, or the skull will not be saved to your profile and you will have to get it again.
Each of the holographic rings sound a different tone of the E Dorian scale when you stand near it. The sequence, if you pay attention, plays part of the Halo theme song. Also, the rings in the citadel resemble the seven installations, with the fourth ring being Installation 04, indicated by its red glow.
Effect
The IWHBYD Skull unlocks the extra dialogue in the game, which usually comes from the UNSC Marines and Elites, but some ridiculous dialogue does come from enemy forces with this skull on. For example if in a group of two Brutes one is killed, the remaining Brute has a chance to say "You killed my lover!" Here is a list of quotes, from their respective races.
Brutes
"Pie is good."
"Sorry, we don't take master card."
"I like chicked nuggets!"
"The power is YOURS!" - When a Brute sticks you with a grenade.
"Ding dong, the demon is dead!" - When a Brute kills you.
Grunts
"You killed Flipyap! Or Yapflip, was he... It was Flipyap... No, Flipyap was his brother. Don't tell me I don't know Yapflip! Flipyap and I went to Nipple Academy together, and, eh, now he's dead..." - If a neaby grunt is killed.
They also say different things while asleep, such as "Merry Christmas".
"We are the champions, my friends." - If the player is killed by a Grunt.
"Well this sucks, I'm headin' north!" - If the player shoots at a fleeing Grunt.
"Fear my bright, blue balls!" - When a Suicidal Grunt charges the player.
"I was so wrong to shoot at you."
Marines
"THIS IS SPARTA!"
"Chief, can we be friends?."
"This is for all the ladies at home I would be sexin' if I weren't here!"
"I loved him." - If the player kills a nearby marine.
"See anything you like?" - When the player walks past the female marine in Sierra 117.
Sergeant Johnson
"That one called you fat Chief!"
Elites
"Chief, can we be friends?"
"Wort wort wort!" - From Halo: Combat Evolved
The Arbiter
"You shot me, fool!" - When he is shot by the player.
343 Guilty Spark
"You suck, Reclaimer." - If the player destroys an allied Auto Turret in front of Spark.
"Maybe you should try playing on Easy." - If the player destroys an allied Sentinel
"That hurts my feelings! ...Oh my God, I have feelings?! I'm a real boy!" - When shot at by the Chief
"Are you always a pain in the ass?" - When shot at by the Chief
"Oh, I see. You're a moron." - When shot at by the Chief
"I'm being bitch slapped!" - When shot at by enemies
