User blog comment:RRabbit42/Disney Halloween costumes for the characters/@comment-419569-20091017024449

Cool! Let me see which ones I can list:


 * Phineas: Mickey Mouse; Pinocchio; Mad Hatter; Peter Pan; Kit Cloudkicker; Darkwing Duck; Bonkers D. Bobcat; Todd Daring
 * Ferb: Donald Duck; Gyro Gearloose; Launchpad McQuack; Captain Crandall
 * Perry: Pluto; Abu
 * Candace: Clarabelle Cow; Cinderella; Princess Jasmine; Miranda Wright; Riley Daring
 * Doofenshmirtz: Zeke Wolf; Captain Hook; Duke Igthorn
 * Isabella: Minnie Mouse (for obvious reasons); Alice; Webby Vanderquack (they already dress similarly!)
 * Baljeet: Goofy; Ludwig Von Drake; Skate Lad
 * Buford: Pete; Monterey Jack; Lucky Piquel
 * Gretchen: Daisy Duck (to match Ferb as Donald, of course); Gadget Hackwrench; Rope Girl (to match Ferb as Crandall)
 * Jeremy: Horace Horsecollar; Prince Charming (the prince from "Cinderella", obviously); Aladdin (to match Candace as Jasmine); Ron Stoppable (to match Candace as KP)
 * Stacy: That princess from "The Princess and the Frog"
 * Suzy: The Queen of Hearts
 * Reginald: Scrooge McDuck
 * Irving: Gladstone Gander

That's all I can think of for right now. If any more ideas come to mind, I'll add them in a later comment.