"Blazing Entrails" is the fourth episode of Season 4.
Ren takes Stimpy to Dr. Brainchild when he starts acting dumber than usual. Dr. Brainchild makes Stimpy's body fifty times large, and Ren has to go inside Stimpy to save his brain from his ignorance gland (but not before getting beaten up himself).
- Dr. Brainchild and his mother are voiced by Bill Mumy and June Lockhart respectively.
- This is the first episode to be animated by the Australian company Mr. Big Cartoons.