Emilio Lizardo

Dr. Emilio Lizardo was an Italian scientist who, with Professor Hikita, was the first person on Earth to penetrate the barrier to the 8th dimension. He was played by John Lithgow in the film.

Princeton Experiment
In 1938, at Princeton University in New Jersey, Professor Hikita and Dr. Emilio Lizardo built a very crude version of the OSCILLATION OVERTHRUSTER in an attempt to demonstrate that a person can pass through solid matter. Lizardo chose himself to be the first to try the experiment. He sat on a sled-like vehicle and started moving toward the wall. Professor Hikita frantically tried to stop Lizardo, since not every aspect of the experiment was ready, but it was too late and Lizardo passed partially through the wall to the 8th dimension. There he was grabbed by alien hands and was possessed by John Whorfin, after which he returned to Earth and appeared to go violently insane.

As Whorfin
see John Whorfin

Practically all deeds done by Lizardo since that time were done by Whorfin. Lizardo and Whorfin regularly combated for the control of Lizardo's body. While they were in a home for the criminally insane in Trenton, New Jersey, drugs helped Lizardo gain partial control of the body but after his escape from the home, Whorfin took complete control.

After Whorfin's destruction
During a pitched battle at Yoyodyne Propulsion Systems, when the Panther ship was launched in an attempt to return to Planet 10, Lizardo/Whorfin and all the remaining Red Lectroids were killed when the ship was destroyed by Buckaroo Banzai and John Parker.

Trivia

 * Neither Whorfin nor Lizardo can drive.
 * Lizardo has a strong Italian accent. Actor John Lithgow imitated the voice of Roberto Terminelli, a tailor on the Fox Studios lot, and had him speak all of Whorfin/Lizardo's dialogue into a tape recorder which Lithgow used to copy the accent. (In the first scene that Whorfin and Buckaroo Banzai shared - where Whorfin tortures Banzai for information - actor Peter Weller frequently burst out laughing at the "Italian/Martian" accent Lithgow was using.)
 * Whorfin's true Lectroid form was never seen onscreen; all we ever see of him is Whorfin possessing the body of Emilio Lizardo.
 * It's never explained how Lizardo does not age after Whorfin possesses his body (Lizardo appears to be the same age in the present time as he was in 1938).