Cotton Spores are event currency for the “More Spores for Hoppip” event (runs until March 25). Trade them at Pokemon Centers for exclusive items.
How to Get Cotton Spores
Visit Dream Islands to collect Cotton Spores. Speak to Drifloon and use a Doll to travel there.
You can visit one Dream Island per day, but return as many times as you want within that 24-hour period.
Cotton Spores float across the island terrain. Walk up to them and interact to collect. Thorough exploration yields 50-70 spores per island.
Where to Spend Cotton Spores
Find Hoppip behind the counter inside any Pokemon Center during the event.
Hoppip sells unique items needed to create habitats for Skiploom and Jumpluff. Buy at least one of everything to unlock both Pokemon.
Total needed: 75 Cotton Spores (a few Dream Island trips)