Septic Man (2013)

Plot

A sewage technician finds himself ensnared in a septic tank amid a severe water contamination emergency. As he struggles for survival, the harsh conditions trigger a grotesque transformation within him. To break free, he forms an unlikely alliance with a gentle giant and must face off against the deranged killer, known as Lord Auch. Together, they navigate a world filled with terror, battling both physical and psychological horrors in a desperate bid for escape.