At over 60 feet tall, the sea strider is the largest life-form found on Darwin IV. It lives exclusively on the gelatinous surface of the Amoebic Sea, whose unique characteristics provide both support for the sea strider's enormous bulk and its sole source of food. The sea strider must maintain constant motion, feeding continuously on amoebic gel that it takes in through mouths on its feet. Behavioral displays include thunderous roars and blue biolights that accent its crested head, back and swaying tail.