The Jack-o-turnip cannot be built year-round. It can be built only during the Halloween season (roughly during the month of October). Watch for updates, may not be available on Xbox 10/2023. Option to build Jack-o-turnip should trigger upon picking up or harvesting turnip. For Xbox it may be necessary to download 'Insider Hub' through the console.
Notes[]
Jack-o-turnips do not frighten boar when nearby, unlike most light sources.