Roggan Streamdiver was a male otter of the outlaw otterclans on Green Isle. After Leatho Shellhound was captured by Riggu Felis, Roggan was among those otters who left Holt Summerdell to battle Riggu Felis and his feral cat army. In the early stages of the initial attack against the cats, Roggan was ordered by Banya Streamdog to take his clan and the Wavedogs along the left side of the Fortress lake, while Kolun Galedeep, his clan and the Wildloughs took the right. Roggan was the only identified member of the Streamdiver clan, and he was only mentioned once.