The cóiste bodhar is a legendary Death Coach. It is an ancient legend of Ireland. The spectral black coach sometimes driverless and sometimes driven by a dullahan, is pulled by black horses, or headless horses, or skeletal horses and comes to pick up the souls of the newly dead.
This is depicted in a very satisfying way in the 1959 Walt Disney film, "Darby O'Gill and the Little People."
Ah, yes. Disney, the wellspring of all our knowledge, folkloric and otherwise. I've actually heard that, in recent times, the newly deceased's souls arise to the firmament in coaches shaped like pumpkins, towed by 101 dalmatians, accompanied by the song stylings of the old bunny-boiler herself, Glenn Close.
Or possibly they are torn to shreds, gnashed to flitters by ghostly Celtic tigers, specially trained for soul-herding.