‘Oh, Clancy!’ (said in an American-Irish accent in the spirit of ‘Oh, you little dickens!’ or ‘Oh, Clancy! Up to your monkeyshines again!’)
Where is this from?
Simpsons. Clancy is Chief Wiggum’s first name.
Not older than that?
The tone, if not the name, goes back to at least 1951 and the Warner Brothers cartoon A Bear for Punishment. The mama bear says “Oh, Henry…” to her husband. I’ve no doubt examples go back decades earlier, likely to the advent of radio entertainment programming. Heck, it could’ve been a punchline for vaudeville sketches.
Is that the one where the stork brings the bears the wrong baby? I think I actually remember that.
You may be thinking of Apes of Wrath from 1959, in which a drunken stork (a recurring Warner gag) misplaces a baby ape and kidnaps and delivers Bugs Bunny to the parents instead. The ape husband’s name was Elvis. It was an okay toon, not great.
The Three Bears characters, in contrast, were in some of the most gut-bustingly hilarious toons Warner ever made and I cannot recommend them enough.
As Brian Ekers pointed out, Warners used the “drunk stork makes baby mix-up” trope a lot, but never with the Three Bears. A Bear For Punishment is about Ma and Junyer attempting to surprise Pa on Father’s Day with hilarous results. Junyer (voiced by Stan Freberg, who also did Pete Puma in Rabbit’s Kin has a memorable line: “Duhhh…G-U-N-P-O-W-D-E-R…tobacco! Gee, I sure am smart. C-A-T…dog! B-A-T…Rhode Island!”