No Place Like Gnome. The Tony Mandolin Mysteries, #12

Six garden gnomes just walked onto Tony Mandolin's front porch and paid him in golf-ball-sized rubies. That alone should have been the first warning. The second warning should have been when the little red-hatted fellows admitted they'd "lost" their pet. a creature so cute it purrs, so cuddly it begs for belly rubs, and so illegal in every known dimension that even Odin personally banned it centuries ago. Meet the brugiti: part kitten, part nightmare, all appetite.
When it gets hungry, it shapeshifts into anything-your neighbor's labradoodle, the barista with the great smile, that hot jogger you wave to every morning-and starts eating. Not nibbling. Eating. Six bodies so far, and the morgue is starting to run out of body bags. Now San Francisco's only PI who can see the monsters (and still prefers beer to magic) has to track a shapeshifting, people-munching myth before it finishes its seven-course meal of Fog City.
With his seven-foot former-drag-queen partner Frankie, a very irritated Norse All-Father tending bar, and a pack of terrified gnomes who faint at the mention of the wizard Bain, Tony Mandolin is about to discover there really is no place like gnome. and absolutely nowhere to hide when their cuddly little pet decides it's time for dinner.