Here is the full list of all 17 Fifo's Night achievements.
Discover the secret rooms of the Masion
Get the Stomp
Get 50 candies of each type.
Defeat 10 Mimic Candies
Discover the secret room of the Library
Defeat 10 Koobs
Defeat 10 Jawies
Get 300 candies of each type.
Get 500 candies of each type.
Discover the secret room of the Graveyard
Discover the secret room of the Crypt
Defeat Chope and get the Super Candy Corn
Defeat Zarzo and get the Super Peeper Mint
Defeat Lifo and get the Super Gummy
Get all the candies from the Candy Room
Bring Candywood back to normal
Defeat 10 Mushgus