We all have that voice in our head that tells us we aren’t good enough, that sows doubt and fear as we stumble along in search of happiness and fulfillment. That voice is louder and crueler for some people, feeling like a separate entity with its own goals and desires. What if that feeling were true? What would your inner critic look like if it had a body, and how would it sound if it had its own voice rather than imitating yours? Writer-director Anna Zlokovic explores these questions in her body horror film Appendage, which had its world premiere at SXSW today. While her gnarly, and occasionally hilarious, externalization of the inner critic is a potent (if unsubtle) metaphor, the film suffers from short-itis, failing to make the leap from intriguing proof-of-concept short to cohesive, focused feature.

Fleshing out (pun possibly intended) Zlokovic’s 2021 short of the same name, Appendage tells the story of Hannah (Hadley Robinson), an anxious fashion designer who struggles to stand up for herself. When she has a glass of wine at dinner with her parents, her mother says, “Don’t embarrass yourself, sweetie.” Smiling tightly and putting the wine down, Hannah appears to be having a panic attack when suddenly something bulges painfully from her side. The same thing happens the next day when her imperious boss Cristéan (Desmin Borges) insults her work. That night, Hannah discovers the source of her bizarre pain: a small, human-like appendage is growing out of the birthmark on her side. The appendage is mean-spirited and foul-mouthed, and it doesn’t like Hannah at all. 

The horror influences at this point are evident — think The Brood meets Basket Case with a touch of Ghoulies thrown in, courtesy of the delightfully grotesque creature effects from Amber Marí Creations. The appendage itself is one of the film’s greatest strengths: Emily Hampshire’s voice work alternates between disturbingly cute and gleefully cruel as she delivers Zlokovic’s cutting dialogue. Though it changes shape and size, growing in power as it feeds off Hannah’s insecurities, the appendage initially appears as a demonic baby, with a gooey, wrinkly face and sharp teeth. It’s a grotesque shock to see it growing out of Hannah’s side, and it’s even more horrific to see it moving on its own after she rips it out. 

Appendage doesn’t really aim for subtlety, nor does it necessarily need to: everyone knows how it feels to do battle with an inner critic, and the fear, disgust, and empathy we feel when we see the concept literalized is enough to carry part of the film. Editor Alex Familian makes surprisingly quick cuts, giving the film a stuttery energy that underscores its wicked humor. However, the movie loses control of its central metaphor as the narrative twists and Hannah’s appendage shifts its focus to other victims. It’s certainly true that your inner critic can affect other people — when your negative self-talk bleeds out into your relationships, it can drain others just as easily as it drains you. But the already thin concept stretches past the breaking point, and the movie runs out of steam with too much time left on the clock. 

While I responded well to the film’s odd humor and idiosyncratic horror sensibilities, Appendage is ultimately a story that probably should have remained a short. The original leans more into Zlokovic’s humor, using its star Rachel Sennott to sell the acerbic comedy, and in under six minutes it manages to hit most of the major beats that the feature does. Short horror films don’t get the attention they deserve, and it’s understandable that a filmmaker would want to expand their concept into a feature. But there’s something to be said for recognizing which format best serves your idea and sticking with it. Still, Appendage is a funny, relatable, and wonderfully icky look at dealing with your inner critic, and I’ll be eager to see what Zlokovic does next.