Pokémon: Did You Knows! - General Pokémon Theories - [Text - Upper-right] Aerodactyle is an extinct Pokémon in the Pokémon universe. What you did not know, is that over millions of years, it evolved into Zubats. Yes, Zubats. [Text - Bottom-right] Same hands, ears, and feet. Wings became back spikes, hair curl spiked, and tail uncurled. Gengar is said to be a shadow Pokémon.
Pikachu's name is a combination of the Japanese onomatopoeia for sparkle, pikapika, and the sound of squeaking, which is expressed as chūchū.
Likewise, there's a theory that the faces on Vanillite, Vanillish, and Vanilluxe are decoys, and the ice crystals seen near their false faces are their actual facial features. | 23 Things You Probably Didn't Know About Pokémon