>>34658091Venonat and Butterfree look really similar to one another, and in Gen 1, Pokemon look like each other after they evolve with few exceptions.
And Cubone/Kangaskhan is more than just a theory. You have Cubone and Kangaskhan being made early in development (their index numbers were less than 20), and then Marowak was one of the last Pokemon ever made in Gen I (index number was around 190 iirc). The point is, Marowak wasn't a concept until late in development, probably because Game Freak thought that showing off a Marowak is odd.
And then you have the Missingo evolves into Kangaskhan glitch. In any case, something was meant to evolve into Kangaskhan. Cubone is the best chance of that.
You also have Giovanni, a Ground-type Pokemon expert, using a fucking Kangaskhan against you in the hideout. He also used a Nidorino against you, but since it evolves into a Ground-type anyway, that can slide. Why would he use a Kangaskhan, unless it was meant to be a Ground-type and evolved from Cubone?
You have the two trainers in Union Cave's basement who ONLY use Marowak and Kangaskhan. Both Pokemon are available in the same locations in various games: GSC (Rock Tunnel), BW & BW2 (Route 15), XY (Glittering Cave), and SM (Wela Volcano Park).
In the latest movie, Ash and Pikachu are walking through various locations, including a valley that shows various wild Pokemon out in the savannah. But Cubone, Marowak, and Kangaskhan are the only Pokemon overlooking the other Pokemon from a cliff.
At this point Game Freak might as well just come out and say that they are related.