Western animation/P

Pa

 * Packages from Planet X - EP06b: "A Night at West Iron High". Dan makes small action figures of his classmates with the use of an alien photo camera, but they unexpectedly come alive.
 * Paw Patrol:
 * Paw Patrol - SE4-EP14b: “Pups Save Tiny Marshall”. There’s a short scene with a shrunken Marshall on top of Skye’ wing.
 * Paw Patrol - SE6-EP12: “Pups Meet the Mighty Twins”. Ella, one of the Mighty Twins, uses her power to grow very huge!
 * Paw Patrol - SE6-EP15: “Pups Save a Giant Chicken”. Same as above.

Ph

 * Phineas and Ferb: Two genius boys create intersting inventions and their sister Candace wants to accuse them.

Pi

 * Pink Panther and Pals - SE1-EP01c: "A Pink and Stormy Night". Mad scientist Big Nose invents a machine that can turn anyone into a monster. He wants a test subject and calls in pizza delivery boy Pink Panther in hopes of turning him into one. However, his efforts backfire and only his dog ends up transforming into a monster. Big Nose's last try results in him turning gigantic and chases his dog and Pinky in his castle. However, his even bigger and angrier wife intervenes, forcing the scientist to pay Pinky for the pizza, who obliges by delivering a giant-sized pizza to satisfy the woman's appetite.
 * Pinkalicous & Peterrific:
 * Pinky Dinky Doo - SE1-EP06a: "Tyler's Tall O'Meter". Pinky runs into some problems when she uses her Tall-O-Meter to make herself gargantuan!
 * Pinky, Elmyra and the Brain: Short-lived spin-off of Pinky and the Brain, where Elmyra is para-giantess compared to the two mice.
 * Pixel Pinkie - SE1-EP13a: "Tall Stories". The protagonist asks her Pixel Pixie, a magical being that can alter reality, make it higher. However, the protagonist grows unexpectedly.

Pj

 * PJ Masks: Three children become super heroes every night while wear pajamas.

Po

 * Polly Pocket (2018): Polly is able to shrink her and in her grasp. There are various para-giantess moments in the series.

Pu

 * Pumpkin Reports - EP09a: "Monster Grow". Teresa grows into a giantess after eating fertilizer.