Clanker aka ATG-3
Clanker is the "official" battle droid of the ATGcast podcast stream. With an alpha-numeric designation of ATG-3, this sardonic droid got his start as a guest commentator on Around the Galaxy episode #133 and ever since then he's been appearing on the show to read listener reviews every other week. He also appears in spots on other ATGcast programs while continually begging for his own chance to host a show on his own.
While there is no proof, Clanker's story is that he was retired after his politeness filter was damaged in the Clone Wars.