- Creator Breakdown: Mark Millar had just gotten some surgery done and was in constant chronic pain when he first wrote the series, pouring all of his misery onto the characters.
- Unintentional Period Piece: Proteus (with his piercings, big sunglasses, toothy grin and football shirt with NTL logo) looks like a Totally Radical advertising mascot from the early 2000s.
- What Could Have Been
- The original pitch by Brian K. Vaughan was very different from the final product by Mark Millar.
- Bryan Singer was supposed to have written 12 issues, but was ultimately unable to commit thanks to working on Superman Returns.
- Marvel proposed Mark Millar to make an "Ultimate Wolverine" comic, but he refused. He wanted to do something with the Avengers instead. Marvel accepted, but renaming them as "The Ultimates"
Trivia / Ultimate X-Men