Elf Hair, Elf Teeth

Elves live hundreds of years, and some grow their hair out for hundreds of years. Meeting an elf with a turban containing dozens and dozens of feet of dreadlock is not uncommon. Others keep a braid wrapped around them like a scarf or shawl. Still others simply let their hair flow down to their feet and beyond, full-on Lady Godiva style.

Same thing goes for elven teeth: to last 700 years they need to either be diamond-hard, or constantly growing, or replacing themselves. We don't want elf bite attacks, nor them to be nibbling like hamsters, so replacement it is. However, unlike sharks, elves are magical. Ergo: once a year, on a specific day, ALL ELVES EVERYWHERE lose all their teeth and regrow them.