Studio Ghibli used to work with Batman the Animated Series and Superman the Animated Series
They're well known work was the show cross over called "World's Finest" and they have already animated few batman episode as well superman so good luck finding which one
This not the end with Ghibli association with Batman because for some reason they keep hiring Batman live action actor to dub they're movies the notable are
Michael Keaton (Who played Batman in Batman 1989) who voice Porco in Proco Rosso
Christian Bale (Who played Batman in the Dark Knight trilogy) who voice Howl in Howl's Moving Castle
Will Arnett (Who Voice Batman in Lego Batman) who voice the Pod in Arrietty
Mark Hamill (Who Voice Joker in various batman media) voice Muska in Nausicaä
Lately the new addition Robert Pattinson (Who played Batman in The Batman 2022) who voice the Heron in The Boy and the Heron
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Thanks. Can you provide some links to the articles of this? But interesting post, keep posting things like this.
https://www.imdb.com/news/ni65427473/
I can't find rest of the episode but the YouTuber "Serum Lake" who content is batman cartoon media and everything about DC cartoon media who also interview the people who work on that those show confirm it
But I don't which video confirm that or maybe his short
As for voice actor you can just googled them