In Far Far West, you have to collect a bunch of Cacti as part of a secret side quest, Cactus Family Reunion, in the Desert map.
You’ll need to match and reunite six small cactus kids with their six larger cactus parents scattered across the sand, then bring each kid back to its correct parent to finish the mission. After completing all six reunions in a single run, it unlocks the Cactus Day Joker, which has a small chance to spawn a cactus-themed Minino around where enemies die later in the run.
