Smat is a robot companion who first appears at the beginning of the series, serving in a supportive role. His design enables transformation into an Ultra Evolution Mobile Z Gear. Typically cheerful and happy, Smat can become strict when necessary. Uniquely for a robot, he is programmed to experience hunger, remedied by scanning matrix barcodes (Z Codes or regular QR Codes) which function as his meals. He exhibits gluttony, demonstrated when unable to refuse an extensive offering of QR codes presented like a buffet.

When merged with the E5 Shinkalion unit, Smat adopts a more serious demeanor while retaining his core personality. His speech pattern usually involves ending sentences with the honorific copula "-de gozaimasu," though less frequently than his predecessor Shashot. During the E5 merger, this verbal tic changes to "-zetto."

Smat shares a voice actor with several characters in different regional dubs, including the Taiwanese and Cantonese versions. His character functions partly as a gimmick tied to QR code scanning mechanics within the narrative and toy line, an element receiving less focus in the show itself compared to the merchandise.