Grasshopper

When he was still alive, Doctor Odd’s grandfather used to begin stories with “Back when I was knee-high to a grasshopper.”
“Grampa, you couldn’t possibly have been so short,” Doctor Odd would say. “That’s the size of a inviable fetus.”
After his grandfather died, Doctor Odd put his brain in a jar, and the speakers attached to the life support generator filled the air with moans and pleas for mercy.
The brain still wasn’t knee-high to a grasshopper, so Doctor Odd worked on a matter-compression laser.
But it just heated the suspension fluid, and boiled the brain in the jar.