Not to be confused with See Dr. Jackal and Hide.
Dr. Jekyll and Mr. Mouse is a 1947 one-reel animated cartoon and is the 30th Tom and Jerry short. The cartoon was released on 14 June 1947, and was directed by William Hanna and Joseph Barbera, produced by Fred Quimby and has animation by Ed Barge, Michael Lah, Kenneth Muse, Al Grandmain along with uncredited animation by Pete Burness. The episode is a parody of Dr. Jekyll and Mr. Hyde. It was nominated for the Academy Award for Best Short Subject: Cartoons in 1947, but lost to Warner Bros.' Tweetie Pie.
Near a basement window are two empty milk bottles whom the milkman comes and replaces them with new ones. Through the basement window, Tom reaches for one of the bottles and then snatches it, rushing into the living room to pour it in his bowl and drink it but Jerry also wants Tom's milk. Tom makes various attempts to catch Jerry, but when they all fail, the cat dreams up a murderous plot to rid himself of his annoyance.
The next scene shows Tom mixing dangerous chemicals such as moth balls, acid, ammonia, and poison into his milk, upon mixing the deadly elixir, the chemicals cause the spoon to dissolve. After seeing a fly taking a little sip from the bowl before crying in pain and then dropping dead, Tom carefully carries the bowl and places it outside Jerry's hole, confident that his potion works, gleefully watching Jerry about to drink from the bowl.
Seeing the bowl of milk once again, the mouse drinks the milk, causing him to yell in pain and collapse "dead". Just before Tom can celebrate over the "dead" mouse, the full effects of the potion take place: Jerry starts to turn into a super-strong mega muscular version of himself who is now more than able to defend himself against the cat, only one thing is on Jerry's mind: REVENGE! Tom panics and backs off as Jerry advances. He first smashes a book from the telephone desk on Jerry, but the book punches through Jerry, who proceeds to rip the book apart. Tom then tries whacking Jerry with a fire poker, but only leaves imprints of Jerry on it. He then rushes and shuts the door to the living room, but Jerry knocks it over, and Tom rushes to hide into the safe, only for Jerry to drill a hole on the safe's door with his bare fist and pull Tom out. Jerry's seemingly infinite strength allows him to smack Tom against a safe, but the potion's effects wear off and Jerry returns to his normal size.
After realizing he can no longer pull the cat around, he dives away from the cat and into the milk bowl. Tom grabs the mouse out of the bowl as he screams and turns into the super-Jerry a second time, whom now grabs Tom and hurls him by his whiskers before the potion wears off. As Jerry realizes he is normal again he simply ties Tom's whiskers and tries to drink more potion. The feline upends the bowl with his foot before the mouse can drink enough, and the chase continues across the kitchen. Jerry first traps Tom's tail into a waffle maker, turning it into a waffle. He then hides in the refrigerator, and as Tom opens to look for him, Jerry is revealed to be at the door of the refrigerator, and kicks Tom in, trapping him inside.
Once launching Tom into the kitchen refrigerator, Jerry hurriedly attempts to make more of the concoction himself, with a different formula such as shoe cleaner, more moth balls, little acid, ammonia, and a drop of red poison (albeit with somewhat inaccurate measurements due to the concoction being rushed by Jerry himself) but before Jerry has a chance to drink it, Tom escapes from the refrigerator covered with food, asparagus out from mouth and steals the milk from Jerry. The mouse tries to run away, but Tom stomps on his tail and forces his enemy to watch as he greedy drinks the potion, thinking that he'd turn into a super-strong mega muscular version of himself. The cat grins evilly at Jerry and as Tom grows to an enormous size, but then an explosion erupts from Tom, resulting in him shrinking to a smaller size than Jerry.
For a second, both of them stare at each other. Then, Jerry realizes much to its delight that Tom is now smaller. Jerry grabs its tail from Tom's foot, causing Tom to lose his balance. Tom, terrified now, tries to run but Jerry holds onto Tom's tail and punches Tom's face. This triggers the cat to shrink more. Jerry then pulls Tom's tail and snaps it. Tom yells in a high-pitched scream and shrinks one last time all the way to the size of a little ant, so Jerry decides to chase ant-sized Tom with a flyswatter.
- This is the third Tom and Jerry short to be nominated.
- Monster Jerry later reappears, decades later in the video game, Tom and Jerry in War of the Whiskers. he is the final boss for all the big characters with the exception of Spike who fights Robocat instead. He is unlocked after defeating him while playing as the Eagle from Flirty Birdy. in Challenge, if Jerry drinks the green flask or is hit by it, he'll transform right back into Monster Jerry.
- The episode's title is a pun on Robert Louis Stevenson's book Strange Case of Dr.Jekyll and Mr.Hyde.
- A shot of the cartoon's original titles were found, but only in black and white. The original Technicolor version hasn't been found as of 2018. On October 7, 2018, a YouTube user cartoon98100 uploaded the full black and white titles of the cartoon taken from a 16mm Agfa print.
- It is unknown that why the fly drinks the milk and then dies while jerry gets extremely strong like Spike.
- The following cartoon shows Tom's size restored to normal after this, meaning the potion is worn off after the cartoon ends.
- For some unknown reason, The Art of Tom and Jerry: Volume 1 laserdisc set in 1993 uses an awfully faded print taken from the Tom & Jerry Cartoon Festival Vol. 1 1982 VHS, despite that almost all cartoons released in the first two Tom and Jerry Cartoon Festival VHS tapes which originally used very inferior prints were given newer video remasters from the late-1980s/early-1990s which looked far superior in the The Art of Tom and Jerry LD sets (with this cartoon and "Cat Napping" from Tom and Jerry Cartoon Festival Vol. 2 being the only two exceptions).
- Despite not appearing in its entirety on the MGM Cartoon Magic Volume 1: Featuring Barney Bear and King-Size Canary 1983 VHS/laserdisc set, a small 1-minute preview clip of this cartoon could be seen at the very beginning of the VHS/LD set before the feature program begins with the Barney Bear cartoon "The Unwelcome Guest" (1945), as an attempt to promote the Tom and Jerry Cartoon Festival VHS tape collection which was released by MGM/UA Home Video at the time. The clips from this cartoon shown in the preview clip were Tom mixing the chemicals in the milk, Jerry drinking the potion for the first time, and a super-muscular Jerry violently trashing Tom for the second time.
- Monster Jerry appears in Tom and Jerry Chase. Any mouse will transform into Monster Jerry after drinking Transformation Drink.
- This is the last Tom & Jerry cartoon to have animation by Pete Burness (although he was uncredited).
- The book that Tom uses to hit Jerry is yellow on the shelf. When he grabs it, the book turns green.
- full original titles by cartoon98100 Note: Only in black & white.