Gah. I must not be reading the right comics, because I have only one Unfunny on-file that could be considered Halloween-related:
From The Brave and the Bold No. 2, back when the book was an anthology about Robin Hood and the Viking Prince and the Glowing Gladiator and so forth, and the dumb cartoons reflected that, which meant humourous comics about horrific bloodsports. Hurrah!