She can feel a hollow vibration,
Her teeth getting yellow and cracked,
Gas pressure's causing head inflation,
Her body sinks in, her green skin drags...
and...her long hair...tears off & goes black!!
Then he farts a big spray as he bounces off the wall,
Wasn't it her...no, him, he's another sick ol' Madball.

To recap, little Samantha, sick of the daily inspection, somehow grows into a life-size version of the Madball, Slobulus. The cruel washer and the other students ask him what happened, but explains he's always been a Madball and he has a feeling more are on the way. Some of said students gave Slob a creepy grin thinking he was right.

He starts screaming & getting stitches,
{A boy loses his hair and his skin gets rough like a baseball as he transforms into Screamin' Meemie}
Her eyes combine & grows horns on her dome,
{An Asian girl drools a lot through her growing sharp fangs and her hair falls all over scaly hair as she bulks up into dude-like Hornhead}
New black and white spots make her look vicious,
{An skinny girl sprouts blue eyebrows, a bleeding pink nose hot orange lips and a dangerous saw-toothed scowl, thus becoming Goal Eater}
Old TP wrapped across his bones...
{A fat boy comicly spits a lot before thinking of his literally lively days in Ancient Egypt as he's now...nay, he is Dust Brain. At this point, that inspector is shocked and surprisingly blown away that the kids were expanding & reverting into Madballs, even though after they change, they sigh and rejoice of being back to their regular forms}
Hey!! Cleaner!! Leave us spheres alone!!
Bouncing off our cares away and re-dirtying this hall,
Not at all do we need these clothes, we're other sick ol' Madballs.

Inspector: You children are happier this way? You should calm down your bouncing. If you don't calm down your bouncing, you won't get to stay neat! Mmm, I wonder how much these gross blokes are on eBay.