Inspired by a commercial for an anti-aging cream on TV, the Mask decides to create his own and test it on himself - only for Stanley to begin uncontrollably de-aging, forcing him and Peggy to find a cure before Stanley regresses out of existence.
Tropes:
- Annoying Patient: The Mask as a toddler is so disruptive that he ends up driving the doctor on duty at the hospital to the brink of a meltdown.
- Baby Morph Episode: The crux of the episode in a nutshell, especially given that the Mask/Stanley regresses from teenager to child to toddler quite rapidly and spends the rest of the episode in various stages of infancy, ultimately being reduced to a newborn before a cure is found.
- Badly Battered Babysitter: Peggy has to play babysitter to the Mask as he gets progressively younger, and unfortunately for all parties concerned, the Mask retains his powers all the way to infancy. As a result, Peggy ends up getting pushed on the swings so violently that she's left hurtling back and forth like the ball on a bolo bat.
- Bathos: Peggy finding that Stanley has seemingly suffered a Death by De-aging and breaking down in tears? Sad. Peggy crying into Stanley's discarded diaper? Hilarious. A doctor revealing that Stanley was just taken away for a check-up - and Peggy throwing away the diaper in belated disgust? Side-splitting.
- Becoming the Mask: After being mistaken for the Mask/Stanley's mother by one of the doctors at the hospital and having to spend the next few hours parenting the Mask anyway just so she can keep him focused on the job at hand, Peggy starts getting a little too into her role - especially once the threat of an imminent Death by De-aging starts to weigh heavily on her mind.STANLEY! I'M COMING, STANLEY! MAMA'S HERE, BABY!
- Cloudcuckoolander's Minder: Since Stanley has no idea how the Mask's anti-aging cream was made, he's forced to cede control to the Mask in the hope that he can make the cure instead and entrusts Peggy with keeping his other self on target. Unfortunately, the Mask as a teenager (and then a child, a toddler, and a baby) turns out to be even harder to control than his adult incarnation, and Peggy is left struggling to keep up with her increasingly childish charge as she tries to get him focused on work.
- Couldn't Find a Tissue: Erroneously believing that Stanley has regressed out of existence, Peggy cries into his now-vacant diaper - and then throws it away in revulsion once she realizes what she was rubbing her face with.
- Death by De-aging: Stanley quickly finds himself facing the threat of getting so young he ceases to exist, and for a moment, it looks like it really happened when Peggy finds his empty diaper with no trace of Stanley himself. Thankfully, this fate is averted at the very last minute.
- Delayed Reaction: After her last-ditch attempt at curing Stanley seemingly fails, Peggy gives up in despair and walks away - only for Stanley to begin growing back to normal. As he ages from infant to child, he tells her that her plan worked, but Peggy has her back to him and is too busy crying to notice the change in Stanley's voice; it's not until she turns around that she belatedly realizes that the "baby" that was about to suffer a Death by De-aging is well on the way to becoming a teenager.
- Dramatically Delayed Drug: When the Mask tests his anti-aging cream on live TV, he opts to rejuvenate himself with his usual shapeshifting antics, so at first it looks like the cream was just a nonfunctional prop. However, when Stanley Ipkiss awakens next morning, he finds that he's regressed to his teenage years overnight, revealing that the cream was real after all, just delayed. Unfortunately, Stanley and the Mask continue to suffer delayed regressions over the course of the episode, leaving the two of them struggling to develop an antidote before they suffer a Death by De-aging. For good measure, the anti-aging cream takes effect with a distinctive glow and Shapeshifting Sound quite dissimilar to the Mask's original demonstration.
- Fountain of Youth: The natural result of the Mask's anti-aging cream. The rest of the episode focuses on him trying to create an antidote and Peggy trying to keep him focused. Of course, Hilarity Ensues.
- Gave Up Too Soon: Variant; after Peggy's last-ditch attempt to cure Stanley's regression via baby wipes seems to have failed, she breaks down in tears and dejectedly walks away... only for Stanley to begin reverting to normal behind her back.
- Hyde Plays Jekyll: The Mask reveals that he's actually very good at mimicking Stanley's voice and mannerisms once he has a latex mask. At the very end of the episode, he uses this to lull Peggy into a false sense of security, right before unmasking himself and dosing her with the anti-aging cream.
- Improbable Antidote: After spending a huge chunk of the episode trying to find an antidote to the anti-aging cream, Peggy eventually realizes that the cure involves swabbing Stanley down with a baby wipe, causing Stanley to return to his true age in a matter of seconds. In fact, it's so effective that the Mask stocks up on a large supply of baby wipes during the finale just so he and Peggy can enjoy their regression together without having to worry about getting too young.
- Is That Cute Kid Yours?: When Peggy takes an increasingly youthful Mask to the hospital, the doctor on duty mistakes her for the mother. For good measure, Peggy actually seems to lean into the characterization as their time at the hospital continues.
- Just Woke Up That Way: Stanley first realizes that the Mask's anti-aging cream is working a little more effectively than its creator intended when he wakes up the next morning to find that he's regressed to his teenage years overnight.
- Latex Perfection: At the very end of the episode, the Mask impersonates Stanley with the aid of an impossibly realistic mask, which he yanks off to reveal himself right before enacting his latest prank.
- The Mind Is a Plaything of the Body: Zig-zagged; The Mask's behaviour becomes even more childish as he regresses further, often losing his grasp of adult language and speaking in the third person. By contrast, infant Stanley appears to retain enough intelligence and memory to make a grab for the Mask and even suggest a potential cure, but - unlike the Mask - he can't even speak.
- Mistaken for Disease: When Peggy manages to drag the Mask to the hospital, the doctor on duty quickly assumes that the green face and unusual behaviour must be due to some kind of illness. For good measure, as she isn't there to actually witness any of the moments when the Mask regresses, the uncontrollable de-aging completely slips her notice.
- Mistaken for Transformed: After taking the now-infant Mask to the hospital to improvise a cure, Peggy wakes up to find that his enclosure is deserted except for empty baby clothes — leading her to tearfully assume that Stanley has regressed out of existence altogether and the clothes are all that's left of him. Fortunately, it turns out that one of the doctors just removed Stanley from the room for a quick check-up and he's exactly the same age he was the last time she saw him.
- Mundane Utility: Despite all the fear and horror they underwent over the course of the episode, Mask and Peggy end the episode by using the anti-aging formula just to have some brief fun as youngsters - once Peggy hears that they have an entire closet full of baby wipes on hand, of course.
- No Antagonist: There's no real villain in this episode, the real threat being the advancing regression that the Mask and Peggy have to cure before it's too late.
- Not So Above It All: After spending the entire episode being the disapproving surrogate mother to the Mask - on top of having to be the Straight Man to the Mask as per usual - Peggy finds herself regressing to her teenage years and liking it, merrily cartwheeling out of the apartment.
- Potty Failure: As soon as the Mask regresses into a toddler, he runs off with a yelp of "Mask gotta go!" Peggy chases after him and scoops him into her arms... only to pull a horrified expression.Peggy: You didn't...The Mask: When Mask gotta go, Mask gotta go!
- Race Against the Clock: With Stanley/The Mask rapidly de-aging, he and Peggy have only a few hours to find a cure before he regresses to death.
- Reports of My Death Were Greatly Exaggerated: Towards the end of the episode, Peggy wakes up to find up that Stanley is gone, leaving only an empty diaper, and she assumes that he's regressed to death. She's left utterly broken-hearted and quickly reduced to sobbing helplessly into said diaper... up until the doctor arrives with the now-infant Stanley.
- Reveling in the New Form:
- Stanley is initially alarmed by the process of regressing, but once he starts wearing the Mask, he quickly adapts and starts having fun — no doubt aided by the fact that the Mask is a bit of a Manchild anyway; he even spends the day playing on the swings with an increasingly horrified Peggy. Indeed, the Mask is having so much fun that it's not until he regresses from toddler to baby that he finally understands that if he doesn't help Peggy find a cure, he'll die.
- After being cured in the finale, the Mask tricks Peggy into getting exposed to the anti-aging formula, and despite her initial dread over what might happen, she's quite taken with her teenage self. After hearing that they have a large supply of baby wipes on hand, she joyfully cartwheels out of the apartment, the Mask pausing just long enough to apply his own dose of formula before chasing after her.
- A Rotten Time to Revert: Stanley's attempt to use the Mask to create an antidote with the power of the Mask goes horribly wrong, forcing Peggy to wait until next morning to try to guide the toddler-aged Mask through making a cure... by which time, a now infant-aged Stanley is back in control, leaving him without any of the Mask's reality-warping powers and only a few minutes left to live at the most. Fortunately, Peggy is able to find a cure almost immediately afterwards.
- Shapeshifting Excludes Clothing: Stanley/the Mask's clothes don't change along with them when they regress, and the Mask frequently shrinks out of his various costumes throughout the episode; in the finale, Stanley is cured and reverts to adulthood... while naked except for the diaper his infant incarnation was wearing.
