Directed by
| Joseph Barbera | ||
| William Hanna | ||
Writing Credits (in alphabetical order)
| Warren Foster | ... | (story) |
Cast (in credits order)
| Daws Butler | ... | Loopy De Loop (voice) | |
| Hal Smith | ... | Elderly Woman / Mr. Hyde (voice) | |
| Rest of cast listed alphabetically: | |||
 |
Don Messick | ... | Car Owner / Dr. Jekyll (voice) |
Produced by
| Joseph Barbera | ... | producer |
| William Hanna | ... | producer |
Editing by
| Joe Ruby | ... | (as Joseph Ruby) |
Production Management
| Howard Hanson | ... | production supervisor |
Art Department
| Dan Gordon | ... | story sketches |
Animation Department
| Richard Bickenbach | ... | layout artist (as Dick Bickenbach) |
| Robert Gentle | ... | background artist |
| George Nicholas | ... | animator |
Music Department
| Hoyt Curtin | ... | musical director |
| John Seely | ... | music supervisor |
Additional Crew
| Lawrence Goble | ... | titles |
| Alex Lovy | ... | story director |
