I feel like I should at least upload something, with how much I'm struggling with figuring out what to draw. So here's a thing I've been working on.
24x24 sprites of diapers in the event I ever want to do that rom hack


In case you forgot about the main gimmick, here's a refresher:
SPECIAL ABILITY - BABY MODE:
-If this Pokemon is wearing a Diaper, they gain 20% DEFENSE, S.DEFENSE, and HP. (Stacks with Diaper Effects)
-If they aren't, they lose 50% DEFENSE, S.DEFENSE, and HP instead, and will instantly faint to any status condition.
But gain 25% SPEED in the process.
-While wearing a diaper, the Pokemon gets a 20% SPEED penalty in any surfing battle (unless they wear a swim diaper)
-If a Pokemon faints while wearing a Diaper, it is destroyed from their held item slot.
-Pokemon can be fully healed with their PP restored by being 'Changed', This is done by interacting with any Changing
Station, and selecting a diaper from your diaper bag and then the fainted Pokemon to fully restore them.


The first 3 rows are kinda like different tiers. Starting with the cheapest and ending with the best.
Diapers come in 4 main types:

Regular - provides slight boosts to all stats but SPD

Fitted - provides slight boost to SPD but reduces DEF and S.DEF

Absorbent - Provides significant boost to DEF and S.DEF but reduces SPD

Pants - provides slight boost to ATK, S.ATK and SPD but drops DEF and S.DEF


For the more specialized diapers:

Pull-Ups - increases SPD, ATK and S.ATK significantly but reduces DEF and S.DEF, also if the pokemon reaches less than 33% HP, they lose their diaper.

Swim Diapers - Wearer takes no SPD penalty in water and instead gets a SPD bonus! Also prevents Leaking, and resists water type moves, but reduces DEF and S.DEF

Budget - reduces DEF and S.DEF (Essentially negating the defensive benefits of BABY MODE) But can be obtained for free at any mart or changing station

I'm still not sure what to do with Cloth. :/

This obviously makes moves like Knock-Off or Trick a lot more powerful as you can potentially cripple a Pokemon with the huge DEF and S.DEF drop (Although the bonus SPD from going diaperless could be an interesting side effect)
Ideally with some specific learnsets, only certain pokemon can learn knock-off, maybe it could be the signature move of a specific line