- Script
- Len Wein (plot); Chris Claremont (plot, writer)
- Pencils
- Dave Cockrum
- Inks
- Sam Grainger; Dave Cockrum (page 2)
- Colors
- Elaine Lee
- Letters
- Karen Mantlo; Bill Oakley
- Editing
- Marv Wolfman
- Genre
- superhero
- Characters
- X-Men [Professor X; Cyclops; Storm; Wolverine; Colossus; Thunderbird [John Proudstar] (death); Banshee; Nightcrawler]; Count Nefaria (villain); Ani-Men [Frog-Man; Cat-Man; Ape-Man; Bird-Man; Dragonfly] (villains); Beast (cameo flashback)
- Synopsis
- The X-Men stop Nefaria's nefarious plot, but Thunderbird dies in the process.
- Reprints
A new original art page 2 was created for this reprint. It was penciled and inked by Dave Cockrum. This reprint is three pages longer than the original story.