A Misfortune of Lake Monsters by Nicole M. Wolverton
Lemon Ziegler wants to escape the rural town of Devil's Elbow and go to college-but that's impossible now that she's expected to impersonate a lake monster for the rest of her life. Her family has been secretly keeping the tradition of Old Lucy, the famed monster of Lake Lokakoma, alive for generations by staging sightings to keep tourists coming. Lemon can't disappoint her grandparents . . . or tell her secret to her friends, including Troy Ramirez, who has been secretly in love with Lemon for years, afraid to tell her lest he ruin their friendship. When a real lake monster starts eating people, Lemon spills the secret to her best friends, and they must figure out how to stop the monster before it kills half the town.
For readers who enjoy Harrow Lake by Kat Ellis, House of Hollow by Krystal Sutherland, Dark and Shallow Lies by Ginny Myers Sain, and The Lake House by Sarah Beth Durst.