The Iron Giant was a solid film, and about as much of a cult classic as a major release animated movie for kids can be. If you’re a fan of the movie, you’re going to be very into this.
There’s a mod for Fallout 4 which replaces Liberty Prime with the giant from the movie. That’s it, really. It makes the same sounds as Liberty Prime normally would, so don’t get too excited about any fresh narration from Vin Diesel or anything, but it’s still fun to see this giant walking around destroying stuff.
There’s an option to remove the nukes from its back too, if you’re a purist. Also, the mod includes both a 2k and a 4k resolution version of the new skin.
If this really interests you, you should probably go and experience it first hand for yourself in-game, it’s worth the few minutes of effort it takes to setup if you’ve got a save file anywhere near Liberty Prime. Otherwise, here’s a video showing what it’s like.
Here’s what happens when the Iron Giant goes stomping through Fallout 4:
You can grab this mod here.