| Issue | #40 |
| Published | May 1989 |
| Frequency | monthly |
| Cover Price | 1.50 USD; 1.85 CAD; 0.60 GBP |
| Pages | 52 |
| Editing | Mark Waid |
| Characters | Gorilla Grodd; Congorilla; Detective Chimp |
| Genre | Superhero |
| Script | Mark Waid |
| Pencils | Bill Wray |
| Inks | Bill Wray |
| Colors | Bob LeRose |
| Letters | typeset |
| Notes | Cover art credits given on the letters page. |
| Characters | Gorilla Grodd; King Solovar; Sir Albert Wesley; Mr. Barwick; Mr. Hughes |
| Synopsis | A retelling of the origin of Gorilla City, beginning with a space traveler who enhances the gorillas' intelligence and who dies by the actions of Grodd. |
| Genre | Superhero |
| Script | Cary Bates; Greg Weisman |
| Pencils | Carmine Infantino |
| Inks | Mike DeCarlo |
| Colors | Shelley Eiber |
| Letters | Agustin Mas |
| Characters | Congorilla; Congo Bill; Doc Kruger; Kawolo (dies); N'Solo |
| Synopsis | Retells the origin of Congo Bill receiving and first using the Congorilla ring, from Action Comics (DC, 1938 series) #248. |
| Genre | superhero; jungle |
| Script | Tom Joyner |
| Pencils | Fred Butler |
| Inks | Keith Wilson [as Kez Wilson] |
| Colors | Tatjana Wood |
| Letters | Janice Chiang |
| Notes | A darker slant to the Congorilla character. |
| Characters | Detective Chimp; Y-Nad; K-Ram; Randolph; Gus |
| Synopsis | Two aliens give a chimpanzee the power of human thought, and the chimpanzee solves a local murder mystery. |
| Genre | Superhero |
| Script | Andy Helfer (plot); Mark Waid [as Rusty Wells] (co-script); Dan Raspler [as Rusty Wells] (co-script) |
| Pencils | Mark Badger |
| Inks | Mark Badger |
| Colors | Robbie Busch |
| Letters | John Costanza |
| Notes | A humorous approach to why Detective Chimp was so intelligent. |
| Synopsis | Includes 4 explanatory articles: Secrets Behind The Goofy Cover; Secrets Behind The Origins Gorilla City; Secrets Behind The Origins Congorilla; Secrets Behind The Origins Detective Chimp. |
| Script | Mark Waid |
| Letters | typeset |
| Notes | Letters from: Mark Lucas; Charles J. Sperling. Also includes information on the next 3 issues of Secret Origins. |