Notes:

Context here

To sum up, apparently when NOA was localizing Pokémon in the USA, they had the staff create a few replacement designs for the Pokémon. One of which that Pikachu was going to look like a tiger with huge breasts.
I am not making this up. Luckily, Gamefreak and PKMN CEO turned down the design. Though imagine that would be Pikachu's final design. It would be uh..weird for that to be Ash's companion.

Should be noted this art is NOT the official replacement design, just the artist's interpretation of "Western Pikachu"