Pumpkin Boss has been scrapped from the game and can no longer be seen in game through legitimate means.
The Pumpkin Boss
The Pumpkin Boss is a mini-boss in build a boat for treasure. This mini-boss cannot be killed and resides in the Pumpkin Boss Terrain. The Pumpkin Boss has two attacks, one where he lifts up the ground and throws it at the player, and another where he shoots lasers. This mini-boss is extremely hard to pass and can destroy boats with ease. Sometimes, however, you can get lucky and pass without much problem.
The Pumpkin Boss can be moved by a chair.
The Pumpkin Boss' bad A.I. causes it to throw grass behind it and stop his laser attack right before it touches your boat/start the attack after it passes your boat.