本 (běn, 'root') +
吉 (jí, 'lucky') for the English nickname 'Benji.' Famous bearers in Chinese subtitles: the dog from the 1974 film and reboots, and Benji from the Mission: Impossible films played by Simon Pegg (often rendered
班吉 or
本吉 depending on dub). The character meanings are incidental — pure phonetic match.