First drawing of The Phantom Blot with eyes, rather than blank eye-holes in his cloak.
Seven separate drawings of the characters. Mickey Mouse, The Phantom Blot, Goofy, Chief O'Hara, and The Mysterious Mr. X are penciled and inked by Paul Murry, and are taken from interior art seen in this issue. Uncle Scrooge and Donald Duck are penciled and inked by Carl Barks, and are taken from Uncle Scrooge (Western, 1963 Series) #53 (October 1964). Black and white on inside front cover.
Likely authors of this story are Del Connell or Bob Ogle. Connell wrote issue #2, while Ogle wrote a number of the ones that followed. Mickey's use of the word "Ug!" (page 14, panel 1) possibly points to Bob Ogle as writer.
An unprecedented-for-the-time, combining of characters from the usually-separate "Paul Murry Mickey Mouse Comics Universe" and the "Carl Barks Donald Duck Comics Universe" in one huge, event-level 32-page story. This would be the hallmark of the Phantom Blot series for its entire seven-issue run.
Ink blot note with the words "You're Next! The Blot." No characters. Black and white on inside back cover.
Eight trading-card size illustrations of Disney characters. Art is reproduced from cover or interior illustrations of Dell and Gold Key Disney comics.
Chip ‘n’ Dale, Mickey Mouse, Huey, Dewey, and Louie, the Three Little Pigs, and the Big Bad Wolf (Zeke Wolf) are penciled by Tony Strobl. Goofy and Pluto are penciled and inked by Paul Murry. Donald Duck and Uncle Scrooge are penciled and inked by Carl Barks.
Reproduced cover illustrations include: Donald Duck (Dell, 1952 Series) #80 (November-December 1961), Mickey Mouse (Western, 1962 Series) #90 (November 1963), Uncle Scrooge (Western, 1963 Series) #47 (February 1964), Mickey Mouse Album (Dell, 1962 Series) #01-518-210 (August-October 1962), Four Color (Dell, 1942 Series) #1039 (October 1959), The Three Little Pigs (Western, 1964 Series) #1 (May 1964).
Set Number 2 featured a similarly formatted series devoted to Hanna-Barbera characters, and appeared on the back covers of some of Western's Hanna-Barbera comics around the same time. There was no Set Number 3, or beyond. Color on back cover.