From VG247: “The Bloody Harvest event is now live in Borderlands 3 and theres a bunch of spooky new challenges to complete.
Once youve completed the Descent into Heck questline, youre free to visit Heck and complete the challenges.
In this guide, well be looking at the Easy as Pumpkin Pie challenge, where youll need to solve a Pumpkin Puzzle. Youre looking for a room filled with coloured skulls and jack-o-lanterns, which you can find in the temple area in Heck. There are some stairs that lead to the back room where you can find these colourful items.”
Source: N4G PC Borderlands 3: Bloody Harvest – how to solve the Pumpkin Puzzle