The 90s straight-to-video horror series Leprechaun was rebooted a few years back, but this is better. A young London couple expecting their first child escape inner-city dystopia for a diddly-dee Irish village when one inherits their aunt’s country pile. However, such unearned property wealth can never go unpunished – especially not in a housing crisis – and inevitably there’s a catch. Local folklore tells of “little people” – definitely not leprechauns – at the end of the garden, who’ll turn nasty if they don’t get their nightly blood offering.

Man of the house Jamie (Douglas Booth) fears he may not be man enough for this particular house. That leaves his heavily pregnant wife Maya (Hannah John-Kamen) alone to fend off all manner of local threats, including, but not limited to, the Whelans, a clan of riotous roofing contractors (Derry Girls’ Jamie-Lee O’Donnell and Kristian Nairn, AKA Hodor from Game of Thrones), headed up by the aggressively avuncular Daddy Whelan (Colm Meaney). He really does insist on being called “Daddy”. By everyone. At all times.

Director Jon Wright has a nice line in comedy-horror, going back to 2009’s secondary school slasher Tormented, and for this he’s reteamed with prosthetics and puppetry experts Shaune Harrison, Paul Catling and Paddy Eason who helped make Grabbers, Wright’s 2012 film about tentacled and teetotal aliens, such post-pub fun.

According to received genre wisdom, it’s always scarier not to see the monster, but Unwelcome eschews tasteful ambiguity in favour of polyfoam beasties that could have scuttled straight off the set of a lost Jim Henson classic. This is Straw Dogs by way of Fraggle Rock, essentially; but the script by Wright and Mark Stay weaves in enough anxieties, both contemporary and primal, to sustain suspense even amid the silliness. It adds up to an enjoyably unpretentious Irish-ish folk horror. And not a shamrock in sight.

• Unwelcome is released on 27 January in UK cinemas.