This anime has some silly moe scenes and a lot of happy crap at the beginning of the arcs. But in the span of 2 episodes, shit hits the fan and well.....people die.

Or Highschool of the Dead.

You make a point. I haven't watched it before but I've heard the opening and it's great. But one thing I do know is that it focuses more on OTHER stuff than actual horror. But I'll check it out.

For me, Corpse Party has the goriest scenes I've ever seen in anime.

or gantz Orrr akira

and i second that in which arcticwolf said

I haven't seen a lot of gory anime shows but the closest thing to gory that I could recommend would be Hokuto No Ken,Attack on titan,high school of the dead,elfen lied or kurozuka

HIgurashi's very gory, but Akira is pretty disgusting in itself. xD; I'd call it more horrific to watch than most of these on this list- don't let that steer you away, though!

In terms of gore, Corpse Party is probably the one with the most.

Higurashi can get real intense.

Heck no.