It's made of crepe paper, it's tubular about 1 1/2 inches diameter about 8 inches long (Down Spaw). It has constrictions about an inch and a half in from each end and is decorated with a shiny decal.
Every one at a Christmas party gets one and they share it with their neighbor at the table. Each one grabs an end and they pull. The cracker then explodes (mildly) and reveals it's contents. A party hat which you HAVE to wear, a lucky charm (which may, or may not be a yellow handbag) and a motto or joke (kinda like a fortune cookie)
Christmas in England couldn't exist without Christmas Crackers.
When my sister was small she collected the charms and made a charm bracelet from them. The charms were mostly plastic but the bracelet (after a few years of collecting) was unique.