This story and other horror-oriented Kirby stories were reprinted by DC in a 70s comic series called "Black Magic", which may have been where you read it. This story in particular has stuck with me for a long time as well. It could easily have been an inspiriation for the Leprechaun series of movies in the 90s (per the fairly grisly Leprechaun revenge.) Still tame by EC standards of course, but from the style I'm guessing this story is from the early or mid 50s so maybe it was trying to lure some EC readers. This kind of horror is very different from Kirby's "Googam Son of Goom" corny stuff, for sure.