Same with TV shows and movies I suppose. I think it’s a neat, less missable, alternative to things like graffitied easter eggs.
I can only think of a few examples like Judy from Cyberpunk 2077’s Ghost in the Shell and Radiohead tattoo that says
there was nothing to fear, nothing to doubt
In Yakuza series, a character’s tatoo is often all over on thier back and represents the person’s personality, idealogy, or role in the story. The tatoo often has a Japanese or Chinese folk lore reference to it