Chamberlain and genealogist of the royal Lord Protector's family on Eldred's planet. Otho was responsible for keeping records of generations of the Lord Protector's line, ensuring the best possible combinations of pairings to maintain the integrity of the Ancient gene in the family. When he came across Colonel John Sheppard, who possessed a stronger Ancient gene than any of the royals in several hundred years, he presented this to the Lord Protector, who wished to make him his son.
However, Otho had his own plans. He conspired with Tavius to murder the Lord Protector, likely by lacing his food with poisons. Tavius would ascend to the throne, and Otho would be given his sister Mara in marriage.
But when Colonel Sheppard presented all the solutions so his concerns in a single vial -- Ancient gene therapy -- Otho ended the previous agreement and took it himself, making him the most powerful wielder of the chair in centuries. Just as he took the throne, however, Dr. Rodney McKay initiated the tower's star drive and drained the Zero Point Module of all power, ending any possible future rule of the Lord Protectors.
Otho came at Sheppard with a knife, but he managed to steal it and cut him with it. Otho, who had also laced the knife with poisons, soon died.
The Tower - Otho discovers Colonel Sheppard possesses a stronger Ancient gene than any in the family for generations, but will not be stopped from gaining as much power for himself as possible.