I love our elf, Jack Candlestick! He's just a $5 stuffed doll and we don't do the tattling to Santa thing but he's so much fun. Ours sometimes bring gifts, mostly dollar store things like blinking necklaces or jingle bells. He also brings little Christmas board books.
Ours is mischievous, too. One day he put red crepe paper all across the kitchen door and sat on the other side of it with a chocolate doughnut so DD had to rip through it : ) He's also drank her chocolate milk while watching the Reindeer Cam and made her sparkly playdoh and snow angels in glitter, leaving the mess behind. Nothing a hand vacuum can't handle!
DD loves telling people what naughty things Jack did.