Opus' appearance changed since his inception - he originally looked like a common penguin, but between 1982 and 1986 his nose grew dramatically (developing its signature bump in the middle, of which Opus is very self-conscious). Mike Binkley, during one Sunday strip, points out the fact that Opus more closely resembles a puffin, a revelation shocking to the sensitive Opus. (In the final panel of the same strip, Opus responds by telling Binkley that he looks like a carrot.) Opus says he is attracted to "svelte buoyant waterfowl".