Bobo. Peanuts/Simon used him as the fall guy to escape the Boulle Behavioral Laboratory. Bobo was taken from the zoo by the MPs under the direction of Dr. Hasslip. Mistakeningly believing that Bobo was Peanuts/Simon, Bobo was taken to the Laboratory. Though to be fair, the lab did not seem that bad of a place.
Peanuts/Simon lied to the Lone Gunmen about Bobo to make them do what he expected. He claimed the KGB had spent just as much money on making super intelligent animals during the Cold War and that they had succeeded in creating an animal assassin. Bobo was supposed to be this assassin, now working as a freelancer, and planning to kill an important French official at the Washington DC zoo.
Of course this was a lie and Byers was beaten and arrested as a result.