Bullbug was a slave in Mytros. He was due to participate in a sacrificial fight for a funeral when Helikaon stepped in to defend the minotaur, managing to secure his freedom in the process.
In return for being saved, Bullbug assisted the Oracle's Chosen in freeing the rest of the enslaved minotaurs in Mytros and then accompanying them to Pamplaxia to keep them safe. He has since sworn an Oath of Service to the group too, and joins the party on their adventures.