>>27700013We're not entirely sure how it works yet.
When Wishiwashi reaches a certain level, it doesn't evolve, but its ability allows it to change into School Form. Nobody knows what the specific prerequisites to this form are, or why it doesn't just evolve instead.
My guess is that it starts out as a Magikarp/Feebas/Stunfisk-esque Pokemon, but because it doesn't TURN into a badass like Gyarados, it gets a form instead of an evolution. Maybe all Magneton-style, strength-in-numbers evolutions from this point forward will be forms.
Things we can probably assume:
>Gyarados' base stats are likely higher than Wishiwashi's-- is this what triggers the change in form? It's very possible that this is a prerequisite.>At least level 50, but the prerequisite is likely much lower (Magikarp evolves at level 20 for example). 
