How not to Summon a Demon Lord (Lizard Transformation)

Here are two versions of the same transformation, taken from the manga and anime of How Not to Summon a Demon Lord. We'll start with the manga, where a character stabs himself with a cursed knife and becomes possessed by--and transformed into--Gregor, member of a race called the Fallen:

Now here is the transformation from the anime, where Gregor has fur: