METAPOD
IN SHOW
WHY YOU WANT A METAPOD
The length between Metapod and Butterfree is a thankfully short one. You want to start with a Caterpie though, and not go straight for a Metapod you caught because move sets transfer. A Caterpie with tackle becomes a Metapod with tackle and that can be the difference between hours of fighting and constantly switching pokemon back and forth, and just hours of fighting.
WHY YOU DO NOT WANT A METAPOD
If you saw a Metapod and decided to completely skip the Caterpie stage, prepare for 3 levels of the most annoying time you will ever have. This is why a lot of trainers decided to always catch the lowest level of the pokemon evolution chain, and work your way up because otherwise you’d be stuck with a Metapod that can only use harden.
IN SUMMARY
The transition between Caterpie to Butterfree had to be marked somehow. Metapod was that way. He served his purpose, and we moved on.