バボラ

Babolat is a Dark Lord affiliated with the Kayblis Faction and a major antagonist in Rance X.A former Oni, Babolat was transformed into a Dark Lord at an unknown point in the GI Era. Upon becoming a Dark Lord, his already large body began to continuously grow in size, causing him to steadily become gigantic. For whatever reason, his brain was exempt from this expansion, leading to it taking up progressively less space inside of his ever-swelling skull cavity and his intelligence plummeting in turn. Over time, Babolat's brain became too small for him to effectively control his body, to the point where even the simple act of moving began to be a mentally-straining task for him.[From AliceSoft Wiki]