The Iron Giant (1999) IMDb
An enormous alien robot lands in Maine in 1957. It gets a big bump on the head though, so it doesn’t remember much. A boy becomes its teacher and the government starts looking for whatever’s been taking big bites out of anything metallic.
The best film I’ve seen in what could be called the typical US feature animation style of the time. Pretty bad character design, nothing memorable about the music, bullshit morality, a precocious kid stereotype, and a mostly unsympathetic villain. The science sucks, the mechanical design is deliberately implausible, and there are serious continuity problems. However, the villain achieves unexpectedly much in getting what he wants, blood and death are not prudishly excluded, there are no musical numbers, and the only problem with the ending is that it makes the same mistake as Nausicaä of the Valley of the Wind (1984).
References here: Hilda (2018).