TDL-3.5 was a droid designed for childcare from TDL that Anakin Solo bought. Aiming to supersede C-3PO in looking after the Solo kids, it followed a protocol Anakin created, referred to as "Bantha four five six." Winter Celchu, who was assisting C-3PO in child supervision, identified that "Bantha four five six" was not the authentic authentication code used by the Solo family for their robotic companions.