A medical Co-bot (robot / non-humanoid robot / drone) that follows No. 21 around wherever she goes, she addresses the Co-bot as "ちびっ子 (Chibiko)", officially translated in-game as "Buddy", the Co-bot serves as her companion and assists her in combat. Typically appears alongside her XXI frame.
Depiction of the Co-bot varies in-game depends on which weapon/weapon skin players equip, it is either painted in black or white, and has a wide array of top/side attachments. But nevertheless the Co-bot is easily identified by its ball-shaped body, the mono eye optic, and the four walker legs.
Not to be confused with the floating drone that also regularly appears alongside No.21, 'Buddy' refers only to the walker robot, the floating drone is a laser cannon. If only the floating drone is present in a post, do not use this tag.
See post #6822721