Is it normal to joke about very dark stuff around people?

me and my best mate always joke about this kind've stuff and i sometimes go way too far then she tells me to shut up and that its discusting but its never around random people unless im in the mood.

Depends on how it's delivered, but honestly I think it can be a good icebreaker in some strange way. It's so outlandish that people know you're not serious, which the sociability it takes to be comfortable doing so emphasizes relatively safe vibes. I think people can be more afraid of the unknown, meaning you're more likely to be turned away from when you're super quiet. You'll definitely annoy some or all people if you do it persistently as the friendship continues, however, again depending on your age. It's also more common than you think with the way our society is...I mean we're a pretty vulgar generation, and in video games especially things like that are simply thrown around quite frequently.

Joking about cannibalism (especially in reference to yourself) really is taboo and asking for "WTF" looks.

But generally speaking, I can find dark humour very funny, depending on how well I know the person and the context of the joke.

you're gonna look like a creep but... at least you're being yourself right?! hah

Good question... how do ppl react?