Professor Tom is a 1948 one-reel animated cartoon and is the 37th Tom and Jerry short, directed by the duo's creators William Hanna and Joseph Barbera, produced by Fred Quimby, and animated by Ray Patterson, Irven Spence, Kenneth Muse and Ed Barge.
Tom is a professor (complete with pointer and blackboard) trying to teach a small gray kitten of a cousin named Topsy. On the blackboard is the lesson, "Mice live in holes, cats chase mice." This lesson is boring to little Topsy, who manages to fall asleep in class, which leads his instructor Tom to tap on the blackboard as if to say, "Hey, you! Pay attention!" As Tom tries to emphasize the lesson, Jerry has managed to write "Mice are very nice." Tom sees this and screams. He is just about to grab Jerry when he takes his piece of chalk and makes a loud screech on the chalkboard, hurting Tom's ears. Tom corners and catches Jerry, but lets him go after Topsy makes another screech on the chalkboard. Tom again teaches his student that cats chase mice and he sends him on his way. The kitten starts to run toward Jerry and when he reaches him, Jerry shakes hands with Topsy. This causes Tom to scream in aggravation and the chase continues.
The chase goes into the living room and Topsy runs into a chair, then Topsy gets stuck between a couch and a table with Jerry helping him get free. The chase goes into the bathroom, but Topsy ends up slipping on the rug and crashing through the glass shower door. Tom runs off to search for Jerry, but finds the kitten faking a shower. Tom gets angry and orders him back to the teaching area. The kitten starts to walk but Jerry is revealed to be under the towel. Tom tries to catch him but fails, then suspects Topsy of having the mouse, when in fact the mouse is behind him. Topsy and Jerry go to the teaching area while Tom searches for Jerry one last time, returns to the teaching area and then screams when he sees him teaching the kitten that, "Cats and mice are buddies, cats and mice are pals, cats and mice are chums." But the lesson is cut short when Tom interrupts. Jerry responds by poking him with the pointer, tickling him. Jerry then hands the stick to Topsy; when Tom realizes that he is being poked by his student, he sends him on his way to catch Jerry, but not before Tom redirects Topsy in the direction of Jerry. Tom then starts to chase Jerry in a circle after handing Topsy a vase. After a few laps around, Tom stands right behind Topsy and points to the vase, then points to Jerry as if to say "Hit it at him". Topsy, thinks as if to say, "Give it to the mouse and hit me.". He hands it over to Jerry and hits Tom.
Jerry runs to his hole and Tom grabs a cigar and begins to repeatedly inhale the smoke and blow it into Jerry's mousehole, but the smoking soon makes him literally turn green with sickness and pass out. Jerry then emerges from the mousehole with a clothespin on his nose seeing a sick Tom. Tom soon recovers and jumps at him, but Jerry stuffs the cigar into his face, making him sick all over again.
Jerry runs back to Topsy, who then grabs him. Tom returns and, realizing that his student has finally learned, shakes his hand, kisses him, and then pats him on the head as if to say "Good job, you caught the mouse!". Afterwards, he holds his hand out as if to say, "Let me have him," but Topsy refuses and releases Jerry. Tom begins to chase Jerry, but Topsy trips him. Irritated, Tom grabs Topsy and begins to beat him. Seeing this, Jerry helps Topsy by breaking the tip of Tom's tail over his knee; Tom screams maniacally in pain and Topsy escapes.
Jerry then runs on a carpet and Tom traps him by rolling it up. As Tom takes the carpet outside, Jerry escapes and even helps Tom throw the carpet (and himself) into a garden pool. Jerry runs back into the house and slams the door in Tom's face and closes the windows before Tom can get in, trapping Tom's fingers in the process. After the front door gets slammed in Tom's face, Tom decides to break the door down. He takes a few steps back to get a good running start, ultimately running towards the door at full force. Jerry sees this through the mail slot and quickly clears the way for Tom. Topsy then opens the door and promptly gets flattened by a barreling Tom. Jerry then runs to the back of the house and stretches an innertube across two posts on the backyard deck. Still running at full speed, Tom plows into the innertube and gets sling-shotted back through the house and through the mailbox with his backside hanging out.
Jerry arrives with a 2x4 board and is just about to whack Tom when Topsy stops him. After petting Tom's backside gently, Topsy gives Tom a solid whack. The little kitten then takes Tom's hat, places it on Jerry's head, and the two buddies walk away, arm in arm. ("We're Off to See the Wizard", from the score of the Wizard of Oz, is briefly quoted on the soundtrack.)
- Because of the United Kingdom's ban on TV show characters smoking, Tom smoking a cigar is omitted from Boomerang in the UK. And also deleted is Tom spanking Topsy.