Plant it to grow Ghost-In-A-Jar. Spooky! This jar contains a ghost! You can throw it to break the jar and unleash the ghost, or instead Drop it gently in front of a Spirit Storage Unit where you can keep the ghost for good.
Ghost-In-A-Jar Seed price in Growtopia: sells for about 2/WL (median of 1 offers from community Discords, past 30 days). Live price chart and the latest buy and sell offers.