BB-00, also known as Boo, was an astromech droid of the BB-series variety. This particular droid was owned by Emil Graf, a cartographer, and was instrumental in maintaining the functionality of their scout ship, the Star Herald.
The debut of BB-00 occurred in the Tales of Wild Space supplementary story featured in Star Wars Adventures (2017) 1, specifically in "Stop, Thief!," which was penned by Cavan Scott and visually brought to life by Jon Sommariva, Sean Parsons, and Charlie Kirchoff.
The designation BB-00 was chosen by Scott as a namesake for his youngest daughter, who is also called Boo.