My class is mostly boys, so these should be a real hit. The girls will like them too, but my boys love Goosebumps and these bookmarks will be great page savers. In fact students are supposed to record all the pages they read in a day. These bookmarks can clip on from the first page read to the last making recording easy; no more remembering where you started.
If the girls don't want anything as gruesome as a bloody eyeball or scary as a bat, they can choose one of the full moon & stars markers.
The bats are my favorite. I, along with several students, am reading Guardians of Ga'Hoole by Kathryn Lasky and the bats fit right in as do the full moons. Don't want to get moon blinked!