What is the first cartoon or movie to use fake swearing? Like the popular cartoon Spongebob Squarepants' dolphin noises. I can only recall that one occurrence. Is there any cartoon in any era with fake swearing? This doesn't mean the speech bubble ones.
I will nervously submit Angels in the Outfield (1951) shown here at about 20 seconds.
No, I can't really back that up. There's about 20 years of sound movies prior to this, and I haven't seen all of them. You could say from 1934 to 1951, since profanity wasn't banned before 1934, but the gimmick might have been used prior to 1934.
A lot of "Popeye" cartoons have that kind of feel, with Popeye's muttering having the same sort of "swearing under your breath" feel, but I've always been able to parse out clean words from the ones I've seen, so they're neither garbled nor swearing.