An ass-monster movie with a big heart and a flared colon, Jacob Vaughan's Bad Milo! is equal parts playful, grotesque, and endearing in telling the story of a milquetoast corporate accountant with a beastly secret. Duncan (Ken Marino) is already under pressure from his wife Sarah (Gillian Jacobs) and his mother Beatrice (Mary Kay Place) to start a family when his bullying boss (Patrick Warburton) starts to make life at the office a living hell. His gastrointestinal issues becoming too painful to ignore, Duncan reluctantly visits an eccentric hypnotherapist (Peter Stormare), who reveals the cause of his growing discomfort -- a diminutive demon that feeds on anxiety has settled in his bowels. Now, every time Duncan gets stressed, the creature goes berserk. The more it comes out to play, however, the more difficult it becomes to control, prompting worries that it may soon attack his well-meaning yet overbearing family. In order to prevent such a disaster, Duncan takes his therapist's advice and befriends the demon, even giving it a name: Milo. In time, Milo seems to become somewhat docile -- if a bit unruly -- but in the wake of a startling revelation about Duncan's estranged father Roger (Stephen Root), the creature sets out on a vicious rampage that could end in tragedy should Duncan fail to act quickly. If the concept of a horror comedy about a demon living in an accountant's colon instantly makes you shrink away in disgust, you might as well simply forget you ever saw this review, because no amount of convincing is likely to sway you. If, on the other hand, your cinematic sensibilities are skewed enough to recognize how such a ludicrous concept could be used as a springboard to explore some of the universal fears that hold us back from realizing our true potential, this quirky little creature feature might just surprise you. Like Frank Henenlotter and David Cronenberg before them, Bad Milo! screenwriters Vaughan and Benjamin Hayes use their horror-flick concept to address some weighty issues in an unconventional context. Parental abandonment, career instability, and fear of adult responsibility all play large roles in the plot of Bad Milo! -- Vaughan and Hayes merely address them in a manner that favors twisted levity over earnest melodrama. Of course, without a talented cast to help them balance the humor and horror, Bad Milo! could have easily collapsed into complete chaos. With the talented Marino at the center of the story, however, the writers give us a protagonist whom everyone can relate to. Duncan is a faithful husband and a hard worker whose only major flaw is his debilitating sense of self-doubt; he's an easy character to root for, and Marino plays him with the perfect amount of pathos. Meanwhile, he's surrounded by a capable group of performers who use improvisation (as evidenced by the outtakes that play over the credits) to give their supporting players real personality. In particular, Warburton, Stormare, and reliable character actor Root get some of the film's biggest laughs, although the true star of the show is a pint-size puppet with a face only a mother could love. Harkening back to the days before cinema was conquered by CGI, Milo is at once adorable and terrifying in his toddler-like behavior, and his voice (provided by Steve Zissis, who also has a small role in the movie) is expressive enough that we know precisely what's on his mind, even if he only speaks in grunts, growls, and coos. Still, with its occasional blast of scatological humor and one particularly graphic death scene, Bad Milo! could prove somewhat off-putting to your typical indie-film fan. For those who prefer their comedy to have teeth, however, this little creature feature is just what the proctologist ordered.