Fancy dress ideas could be taken from history books,or it can be a character of your favorite movie or television serial or characters from the fairy tales ,cartoon characters,animals etc.
But to think of something different, probably you could dress them up as an object, or create your own new character that could make a difference to the present world situation.
A few fancy dress ideas for Fancy Dress /Halloween for kids include Sponge Bob Square pants, Carly Shay from iCarly, Hannah Montana, Buzz Light year, Woody, Dora the Explorer, Harry Potter, Barbie, Transformers, Indiana Jones ,Pirates,Mickey Mouse ,Tinkerbell, Cinderella,Snow White etc.
They can be dressed up as objects like NewsPaper,Book,Pencil,Cell phone etc.
My daughter dressed up as Goddess Fairy for Halloween Party in School
My Best Friends Son dressed up as a krishna for Janmashtami
This is reaching Artsy-Craftsy-January-2011 "Fancy Dress"