From Aozora Wiki
Paku-Chan (パクチャン, Pakuchan) is a major supportive character in the Aozora's Adventure series.
Paku-Chan's main structure consists of a long, metallic body with rounded sides, which the center opens to enable speech. The eyes are used in the format of blue-colored LED's, which light up in various styles to indicate his expression(s). In a normal state, the LED's illuminate to form two straight, vertically-running lines. Paku-chan is limbless, having detached feet and hands.