Funny costumes can lighten the mood at all types of events; they're terrific for Halloween parties and other holiday celebrations throughout the year. They're . Top 13 DIY Funny Adult Halloween Costumes for Men. From downright shocking to ROFL hilarious, these funny adult Halloween costumes will be the topic of water cooler conversations for days, or even weeks, after Halloween. There’s no doubt you’ll be the center of attention when you walk into a party dressed in one of these outfits.