They used to just do stuff like this to half the dex, the modern games generally having actual moveset curves is really so huge for gameplay feel (yanma's case remains funny though because wing attack is still locked to being a level 43 learnset move even in gen 9 for whatever reason)

Mega Klinklang wasn't a drawing based on a revealed silhouette, but iirc it came out in the middle of the XY mega hype where fake mega leaks were showing up all the time. It's sooooo funny

Perhaps a pokemon leak only rivaled in lasting influence by Mega Klinklang