Pokémon Black & White (be warned: spoilers)

[Wes]

It seems that way doesn't it? But look deep inside that insane knightly armor you can see the original bug Pokemon. My theory is we have a Shelder Slowpoke relationship going on here. After 616 evolves it leaves it's shell behind then 588 picks it up and uses it as it's own armor.

I see what you mean. Zoomed in, I can tell the 2nd stage that looks like a knight has a blue body with a yellow belly underneath the armour, the same colouration as its pre-evolution.