Welcome to Halo Answers. What would you like to know?

There is a 14th one, but it isn't available on the campaign options menu. It's found on the level Cortana, and carrying it to the end will make you start the next level with a Spartan Laser and your secondary weapon you had on the level Cortana. The effect on your HUD is the same as the Blind Skull if you pick it up. There are also Mythic skulls found on the Mythic map packs and if you pick them up you'll get achievements.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.