At Manticore X8-621 was a Member of the bugle corps.
After the destruction of Manticore he, carrying his bugle, escaped along with the other transgenics. He found himself with a group of four X6s and one X7, after the X6s robbed a small store they hid in a barn where Alec McDowell found them.
Alec informed the group that Manticore wasn't under attack and the signal that they had spotted the night before was bogus, though the X6s refused to listen his words rang true when they along with Bugler approached the destination. Max Guevara rescued them and they retreated to the barn, there Max named him after his bugle.
Later they were betrayed by their X7 member and Max was captured by Ames White. He along with the rest of his group helped Alec rescue her. Afterwards he and his group met up with Logan Cale who obtained false documents for them allowing them to escape to Canada. Before they left they paid tribute to their dead transgenics brethren and Bugle played ‘Taps’ (the customary U.S. military funeral bugle call) on his bugle.