When Rogue is sitting on the airplane's wing on her way to Muir Island, a man spots her, panics, and flags down a stewardess. In turn she laughs and walks away in disbelief. This is a reference to the infamous The Twilight Zone (1959) episode Nightmare at 20,000 Feet (1963) starring William Shatner.
First appearances of Apocalypse (En Sabah Nur), Angel (Warren Worthington III), and Moira McTaggert. Pyro (St. John Allerdyce), Avalanche (Dominikos Petrakis), and Mystique (Raven Darkholme) make their first full appearances, after cameos in Slave Island (1993) and others.
Dr. Adler resembles Albert Einstein and speaks with a German accent.
A background character on the airplane is similar in appearance to the man who is removed from the courtroom during Beast's bail hearing, just before Sabertooth's attack, in Enter Magneto (1992).