Void Pumpkin

Void pumpkins were used in the 2020 Halloween Event to build the ships Naga and Incarnate. It was only dropped by the Rift Guardian and Rift Custodian which gave 1 and 3 respectively. Seeing as they were rarely dropped, they were highly sought after and "vulturing" was at an all-time high during the event. Selling one of these pumpkins would give you a lot of credits and is very profitable to sell.