"Is Koffing a rare Pokemon?"

#PokemonGO: I've traveled to various places across the country since the game's release for various reasons, and have had the ability to observe different spawns in different biomes across the country. I've noticed varying spawn rates for many Pokemon, but I noticed that Koffing is extremely rare wherever I go. I've never seen a Koffing nest and they have never been one of those "common" spawns for me. Is this true for anyone else or do I just happen to not be going to the right places. via /r/TheSilphRoad http://ift.tt/2hMsImF