Comment by Sh unashamed on That Time I Got Reincarnated as a Slime - chapter 15

That just depends on the romanization, in Japanese they have L/R as the same "sound" if I say it like the dumb person I am. It's in between those two. Plus they tend to add "uh" at the end which we don't do (when reading english for example), so Gabil is the same as Gabiru