Rimuru Tempest (リムル゠テンペスト Rimuru Tenpesuto?) is the main protagonist of That Time I Got Reincarnated as a Slime and the reincarnation of Satoru Mikami.

In his regular form, Rimuru takes the appearance of a usually spherical and sometimes amorphous mass of slightly blue and translucent ooze. Initially, Rimuru’s slime form has a diameter of around 40cm, this increases to 70cm after his evolution to Demon Slime and further increases to between 80-100cm after his reincarnation to Ultimate Slime.