Gigantic, genetically modified piranha chomp their way down Venezuela's Orinoco River in another deliberately over-the-top creature feature from the company that brought you Mega Shark vs Giant Octopus. As diplomats and even helicopters fall victim to the rapidly growing eating machines, it's up to a female scientist (1980s pop star Tiffany) and a special agent (Paul Logan) to try to prevent them reaching Florida. While the ultra-earnest leads compete for the title of "most hammy performance", a brainless script and ludicrously un-special effects recall the worst excesses of 1950s B-movies. With realism entirely absent, the mutant fish look particularly ridiculous, consequently swinging between giggle inducing and totally derisible. Nonetheless, writer/director Eric Forsberg revels in the film's absurdities, delivering the frantic events with a mock seriousness that heightens the cheap fun. Those who follow the "so bad it's good" school of thought will probably love it - anyone else should avoid.

When a science experiment goes horribly wrong, gigantic fish gain appetites for human flesh.