It's true that a lot of isekai protagonists could be described as pigs, but usually it's not THIS literal.
BUTAREBA: THE STORY OF A MAN TURNED INTO A PIG (Buta no Reba wa Kanetsu Shiro), based on the light novels by Takuma Shikai and illustrations by Asagi Tohsaka, with art by Minami. First published in 2020 and first published in North America in 2024.
PLOT:
Once he was a man who happened to eat some raw pig liver. One moment he passed out at the rail station, the next he was reborn as an ordinary hog in a world far removed from modern-day Japan. It's there that he meets Jess, a slave girl who is able to hear his thoughts and thus realize he is not just some pig. Before they can work on changing him back, he'll need to help Jess with a scheme to obtain a magic crystal, a scheme that threatens to become deadly for one of them.