WAH-loween (sometimes referred as either WAHloween or WAH-Loween) is the name used to describe October 2017 in MFGG. The name was invented by Pedigree. The event was to celebrate both the 25th anniversary of Wario's debut in Super Mario Land 2: 6 Golden Coins and Halloween, with related content and activities taking place, including:
- Isometric Collaboration #9: Happy WAH-Loween!
- Minigame Competition #4 - 2017: Spooky Hijinks
- Sprite Competition #6 - 2017: Monstrous Transformations
- The WAHloween main site skin
- Drawing Competition #7 - 2017: Luigi's Mansion 3
- Music Competition #2 - 2017: Ghost Houses