There were not one, but two Fatty Finn films. First a silent film.
This is the intro to the film and a clever piece of animation and we see 'Fatty' talking with Syd Nichols.
The Kid Stakes (Australian Silent Film, 1927) Part 1 of 6
https://www.youtube.com/watch?v=y2z0s2wCISg
and this one in about 1980. Somewhat Camp.Fatty Finn 1980 Trailer
https://www.youtube.com/watch?v=HNqM0jZiv9k
Note to the WOKE:- Finn is not Fat, the nickname is in the Cockney/Australian tradition of giving someone a nickname that is the opposite of the individuals real characteristic.
Link to the comment: FATTY FINN'S COMIC vol.3 no.7
Thanks for the links to the films. That 1927 film is quite like MGM's shorts series, "Our Gang". from the 1920s through early '40s. And the comic strip had a bit of the flavour of The older Ginger Meggs comic strip.
And the nick-naming of the person as the opposite of his/her qualities was not just a Cockney tradition, but an England-wide tradition (note "Little John" in the Robin Hood Tales), and we have it in Holland and Germany as well. I think it's a fairly old tradition in all The Germanic countries, and France, too. I, myself had the nickname "Black", and it wasn't from being a bad or mean-spirited person, and I am
(was) a redhead, with pasty-white skin (almost an albino).