Opus was originally introduced in June 1981, as a one-time gag about hapless Mike Binkley bringing home what he thought was a German Shepherd, which turned out to be a penguin, much to the disappointment of his father. After being featured in a few strips, the character was dropped for several months, before being gradually re-introduced in January, 1982, and eventually becoming a central character in Bloom County. Opus' popularity quickly grew until he became the signature character of Bloom County and of Breathed's subsequent comic strips.