What sketch show was this from?
I remember seeing a parody of Oswald on TV a long time ago where Oswald, Daisy, and that little wiener dog character were sitting on a boat together. Daisy sarcastically points out that Oswald is an octopus so it makes no sense for him to wear a life preserver. She then pushes him into the water out of curiosity as to what would happen and accidentally ends up killing him in the process.
That totally sounds like something they'd do on MAD but sure enough I dug through the entire catalog of sketches on MAD Wiki today and couldn't find anything about an Oswald sketch.
I don't believe it was Family Guy either because I highly doubt the 80s cartoon obsessed writers of that show are even aware of Oswald's existence. I just think that such a reference seems a bit too out of left field for the typical Family Guy viewer seeing as how the show generally tends to cater to the those who grew up in the He-Man generation of cartoons with it's references.