The pumpkin-derived lantern is "Jack 'o' Lantern" in game. That shouldn't be a quoted "o", it's the Irish patronymic prefix, or alternately an elision for "of the". Any of the following versions would be reasonable:
Jack O'Lantern
Jack o'lantern

jack o'lantern (that is, capitalized only when any word would be, and only the J)
jack-o-lantern (for those too poor to afford apostrophes )
jack-o'-lantern (Wikipedia uses this one)