Always, always, they return Trick-Or-Treating to Threed every year. Why? Because zombies aren't as creepy as Happy-Happy Cultists.

Paula = Carrie White of Stephen King fame. (And hey, they're both psychic!)
Ness = Indiana Jones (Popular costume this year...)
Poo = Erik/The Phantom of the Opera. (Needless to say, the Dalaam girls still swoon over him)
Jeff = Who you gonna call? GHOSTBUSTERS!

Plugging in a cameo appearance with my favorite Mother 1 characters Loid and Pippi, dressing up as the Scarecrow and Dorothy from the famed Wizard of Oz.