#014: Kakuna
Whereas most pokemon transform 'cleanly', both Metapod and Kakuna leave behind remnants when they evolve: an empty carapace that looks unpleasantly like a cadaver. For Butterfree this is an unwelcome reminder of a lowly, wingless existence, but for Beedrill it is a useful tool. In the first months after evolution Beedrill are still uneasy on their wings - a major problem for a predatory pokemon. Until they are used to flying at high speeds they rely on ambush tactics, stuffing themselves back inside an empty Kakuna shell and peering out through its translucent eye-holes, watching and lying in wait. One would think that other pokemon would learn not to go near Kakuna, as we humans did when we were still living in caves, but it seems birds in particular find them tasty, enough so that they will take the risk. This is likely an intended characteristic- it makes life as a Kakuna more dangerous, but ensures survival if it manages to reach evolution.
The existence of Kakuna (and Metapod) shells creates uncomfortable questions about the nature of evolution. If so much of this pokemon is left behind when it evolves, does it mean the creature that emerges after evolution is not the same being ... the same soul? Is the shell of a Kakuna truly its corpse?
Few believe this to be the case, at least not as a general rule for all pokemon, since with few exceptions pokemon seem to retain their memories after evolution (although they often have very different personalities). Some anti-trainer groups have seized onto the example of the cocoon pokemon, arguing that causing a pokemon to evolve is tantamount to killing it. Until the process is better understood it is impossible to entirely discredit their belief. So far, the blinding flash of white or red energy that occurs during evolution has prevented thorough study, but a scientist in Cerulean City claims to be getting close.