In the pilot episode titled Darkly Dawns The Duck, Darkwing says to a criminal in a jail cell, "I don't stand a chance against gorillas like you" which is a racial comment. This line was cut from the dvd release and Disney+ version but is left intact on the VHS release of this episode.
Oh God is said once in the episode titled Tiff Of The Titans.
One of Darkwing's catchphrases which is a recurring one in nearly every episode is "suck gas evil doers".