A holographic villager in Tom Paris's Fair Haven programme who catches Harry Kim's eye and is briefly transformed into a cow as a prank, alarming the other townspeople.
Maggie O'Halloran is a character in the Irish village simulation Fair Haven, played by Henriette Ivanans. She is first seen in the sixth-season Voyager episode Fair Haven as one of the townsfolk the crew meet in the pub and on the street.
In Spirit Folk, Harry Kim takes her for a walk and is about to kiss her when Tom Paris, watching from hiding, alters her subroutines so that she becomes a cow. The prank is seen by the villager Seamus, and although Maggie is changed back she is left with a hazy memory of a strange dream.
Because the programme has been running too long, its characters have begun to notice such oddities. Maggie's story becomes one of the main proofs offered by Seamus and Milo that the visitors from Voyager are spirit folk with unnatural powers.