因瘋狂想法而被地上人們排斥的科學家來到了下水道生活，並且他在這裡邂逅了最愛的生物，巨大下水道鱷魚!! > 藉由科學家瘋狂的基因與機械改造，一隻隻凶狠的改造鱷魚從陰影裡爬出，當鱷魚大軍成型，他在下水道四處放置了炸彈並誓言要報復地面上的城市，到底羅賓要如何解決這次的危機呢?
SHUNNED by the surface dwellers for his twisted brilliance, a mad scientist sought refuge in the filth of the underground. There, in the damp darkness, he met his greatest obsession: the MEGA-GATOR!! Through grotesque genetic splicing and heavy cybernetic grafting, an army of savage mutants has crawled from the shadows. With the city’s foundations rigged to blow, the madman vows REVENGE on those who cast him out. Can ROBIN stop this subterranean nightmare before the city crumbles?
