Lilly Petersen is pretty sure nothing very cool ever happens to her. The only cool thing was being in third grade this year. That makes her an "official" big kid at her school. Everything soon changes for Lilly when she finds out that real live goblins live in the oak tree in her back yard. The idea of having them for pets sounds just perfect to her but.....she wonders about a few things. 1. Do they bite? 2. Are they friendly? 3. Could they help her get rid of her creepy twin brothers? 4. Could they give a kid weird green warts? Lilly will find out the answers to all these questions and more when she realizes she's.......GOT GOBLINS