The upcoming film Detective Pikachu is based on an unusual video game in the Pokemon franchise. When the game was first announced, a grassroots campaign sprung up around the idea of having Danny DeVito voice the little yellow fuzzball for the English language version of the game. When fans learned a movie based on the game was also being made, the demand for DeVito only increased. While the role ended up going to Ryan Reynolds, it turns out that the idea of casting DeVito was at least briefly considered by the filmmakers. According to producer Cale Boyter...
We definitely thought about it and how it might inform the spirit of it. Danny is incredible by the way. I am a huge fan of Danny DeVito.
Danny DeVito's gruff voice is probably the last one that you'd expect to come from the cute little Pokemon, but, of course, that's the joke. He has the perfect voice for a gravely noir detective character, and Detective Pikachu is certainly meant to be having fun with that concept. A Pikachu that sounded like DeVito would certainly come across as something out of a Raymond Chandler novel. Also, hearing Danny DeVito say "pika, pika" would be pure comedy.
How close Danny DeVito actually came to being cast is far from clear, but we do know that this wasn't simply a brief consideration that was discarded quickly. VFX Producer Greg Baxter told GameInformer that his team actually went as far as to add dialogue from several different potential voice actors to an early version of Pikachu in order to get an idea what it would look like. It turns out DeVito was one of the voices used. According to Baxter...
It was really very funny, so I couldn’t speak to all the reasons why it wasn’t Danny DeVito cast. I love Danny and some point maybe after the movie comes about, we can share those early tests. It’s absolutely hilarious.
It would be great to get those tests as part of the special features on a future Detective Pikachu Blu-ray. There were probably several other great actors used as tests that would sound hilarious coming from Pikachu. Until then, we can get an idea what DeVito might have sounded like thanks to fans who added the actor's voice to the character back when the Detective Pikachu video game was coming out. Check it out.
Why Danny DeVito ultimately wasn't chosen for the role we don't really know, though the producer says that the "spirit of Danny DeVito" is still part of the character, whatever that means. I suppose we'll find out when Detective Pikachu hits theaters in May.