Sometimes the mums are bigger than the girls who wear them!
There's a whole hierarchy in sizing, too. Freshman wear single flower mums, sophomores double, juniors triples (Mickey!!!), and seniors are the biggest.
People put all kinds of dangly charms and ribbons and sparkly things on them. Stuffed animals. Battery powered twinkle lights. There was one I saw last year that had a stuffed animal attached to a battery powered motor that rotated it in circles. The biggest ones require a harness-type contraption to wear.
It's nuts, but a fun (and expensive) part of a Texas homecoming!