Frank Baxter
Himself
Richard Carlson
Mr. Fiction Writer
Mel Blanc
Squirrel / Turtle / Alligator / Rabbit (voice)
Sterling Holloway
Lab assistant
Marvin Miller
Hemo / Professor Anatomy
Animation
Family
Hemo the Magnificent
Professor Frank Baxter and some animated friends answer questions about blood. what makes it red? Why do little animals' hearts beat so quickly? And so much more.
