After accidentally falling out of a circus train, the titular Jumbo, a baby elephant, ends up in the residence of Tom and Jerry, where he immediately finds a new friend in the latter and avoids detection from Tom by being painted to look like a mouse, resulting in a series of antics involving Tom mixing up the rodent and pachyderm.
Tropes:
- Agony of the Feet: Not long after giving Jumbo his paint job in the closet, Jerry clobbers Tom's foot with a hammer when the cat opens the door and sees him twice.
- Ass in a Lion Skin: Jumbo lets Jerry paint him so that he looks like an oversized mouse. At the end of the cartoon, Jumbo's mother joins the two, all but completely reducing Tom into an insane, cackling wreck.
- Elephants Are Scared of Mice: Completely averted, as neither the titular Jumbo nor his mother are afraid in the slightest of Jerry, even going along with his idea to disguise them as bigger mice.
- Forcibly Formed Physique: While reaching for Jerry in a mouse hole, Tom grabs Jumbo's tail instead and, thinking he's caught the mouse, pulls the elephant out, stumbling backwards with Jumbo in his grip before being crushed against the stairs by him. In addition to being flattened, Tom is also kinked in the shape of the stairs.
- Laughing Mad: After encountering not just Jerry and the disguised Jumbo, but also the latter's disguised mother at the end of the cartoon, Tom slowly but surely goes into a crazed laughing fit.
- Mama Bear: When Jumbo's mother jumps out of her hiding spot behind her son and Jerry, disguised as a mouse by the former, she looks visibly pissed at Tom.
- Mouse Hole: To Tom's horror, he encounters a bigger mouse hole next to Jerry's, obviously belonging to Jumbo...
- Mouse Trap: ...so he brings in an equally massive mouse trap in hopes of trapping the giant "mouse". However, Jumbo flips the trap backwards and sucks Tom toward it, resulting in the cat receiving a nasty snap on his behind.
- Oh, Crap!: Tom panics when he sees Jumbo's mother behind Jumbo and Jerry, mistaking her for another giant mouse.
- Parents Know Their Children: Jumbo's mother is still able to recognize her son through his mouse disguise when they finally reunite.
- Pathetic Drooping Weapon: Tom chases Jerry and Jumbo, a baby elephant disguised as a big mouse, with a shotgun. After the baby's mother decided to help disguised as a mouse too, Tom's shotgun wilts before Tom runs away Laughing Mad.
- Sanity Slippage: Poor Tom completely loses his marbles when he encounters what he thinks is an even bigger mousenote and runs off into the distance, laughing like a madman and breaking through fences along the way.
- Screw This, I'm Outta Here: At the end of the cartoon, thinking that he has another giant "mouse" to deal with, Tom goes completely insane and retreats into the distance.
- Something Else Also Rises: Inverted. When Tom sees the 'giant' version of Jerry, the barrel of his gun suddenly goes limp in a suggestive fashion.
- Tap on the Head: When Tom opens the closet door and sees the disguised Jumbo for the first time, the little elephant hits him over the head with the hammer that Jerry used to hit his foot.
