Anyone else having issues with this achievement? I have played this level so many times and followed the proper checkpoints. I couldn’t get the seventh checkpoint to trigger any of those times. Finally did another couple run thrus and got the seventh checkpoint to trigger…and still got NO skull. Anyone else have this issue or know what to do about it? Or is this one of those “issues” they are planning on fixing with the update?
The “7 checkpoints” needed to trigger the skull is not true, check halopedia. You simply need to trigger certain loading points for a 1/7 chance of obtaining the skull.
I had many problems with this achievement in the beginning. But I followed ign’s instructions last week and it worked! Dont give up!
And you dont have to fight all waves after picking up the skull.
It took me a long time to unlock that achievement, there is no a way to predict with 100% of accuracy when the skull appears, you have 1/7 of chances… There is no method, just play over and over the mission until you get it… good luck!! 
Thanks everyone! I’ll have to check the ign’s instructions and try that
Well I have tried several more times, even the new way several more times. I have only gotten the seventh checkpoint to trigger 2 more times and still haven’t gotten a skull to pop up…
You can try that : https://www.youtube.com/watch?v=OVZmi0TrrVY
The idea is just to delay a checkpoint right before the sniper alley checkpoint, then save & quit (I don’t think it’s needed but it’s for security I guess) , starting from that save and heading for the skull, still delaying checkpoints (again I don’t think it’s needed if the skull is going to spawn, just security) .
If it’s only for the achievement, the other part is to actually have a save with IWHBYD spawned.
This isn’t something that requires a fix as it’s working as it did just like in the original game. You need to get lucky with all the triggers and stuff for the skull to show up basically. Good thing is that once the skull appears you only have to pick it up to unlock the achievement and don’t need to fight any of the Elite waves.
I don’t with you, by any chances, are you trying to unlock the skull with skulls enabled specifically the one you’re trying to unlock? I went through all 7 checkpoints with no luck until I went back and disabled all skulls except the Scarab skull and from there, the IWHBYD skull unlocked for me.
I’m not sure if this is the solution, but you may need to do this over and over again in order for the skull to spawn.
FINALLY GOT IT!!! Whoot Whoot! Thanks everyone! I didn’t do anything different so I must have just gotten lucky this time lol.
I finally got it use this method I found today on YT:
Been trying for a long time to get it on my roommates account. Hopefully might be helpful to others needing it.