Manga only. Chapter 40, it's pretty bad so I'd suggest you skip this chapter all together, especially if transphobia and stuff triggers you. There is some semi plot relevant stuff near the end of it that doesn't have to do with it, though, so you're safe to read the last 4 pages of the chapter.
episode 1 shows a kid shooting a pigeon with a crossbow and killing it on screen.
demons possess dead animals (dogs) and the look of the corpses is pretty graphic, this happens as early as episode 2
A brief scene in episode 14 has a character see a spider and scream and get scared. Also, near the end of the anime, a villain shows up that uses spiders and spiderwebs to attack.