The definitions of ‘spawn’ and ‘biome’ are blurry, so it helps to set them straight.
- A ‘Spawn Point’ is a fixed location that regularly generates (‘spawns’) a Pokémon.
- A ‘Biome’ is a property of a spawn point that determines what Pokémon that spawn point generates.
A biome should not be thought of as a real world environment or terrain type. It’s a property of a spawn point, nothing more. A spawn point that is of the Water Biome will spawn water Pokémon regardless if there is any body of water to be found anywhere near that spawn point in the real world.
Water Biome Spawns Points do tend to be found near bodies of water, but a body of water is no guarantee for Water Biome Spawn Points. Very often the spawn points near a body of water are simply Common Biome Spawn Points, too.
Grab bag definition
Biomes tend to spawn Pokémon from a grab bag: A list of dozens of Pokémon that all have a chance to spawn of less than 1%. Not all biomes have grab bags and not all biomes have the same grab bag.
Three kinds of Common biomes ?
All of which have at least 20% chance to spawn a Pidgey, but they can be distinguished by how often (or how little) they produce Rattata, Spearow, and Weedle.
|Pokémon||Type 1:‘Grass’||Type 2:‘Bush’||Type 3:‘Forest’|
All three types of Common Biome Spawn Points have around 10% chance to spawn a Pokémon from a ‘grab bag’: A list of dozens of Pokémon that all have a chance to spawn of less than 1%.
The Water biome ?
Which is the only type of biome which does not seem to have a ‘grab bag’. It spawns a water Pokémon 99% of the time.
Water biomes mostly appear near bodies of water.
The Drowzee biome ?
Which has a considerable ‘grab bag’: Almost 30% chance to spawn one of dozens of Pokémon who all have chances to spawn of less than 2%.
Drowzee biomes seem to appear in cities.
The Mountain biome ⛰