Want to kill something? Just buy a can of chewing tobacco, add I would say, 1/4 a cup of water, and just let it sit there for a good long while until the water is nice and dark. Nicotine is more deadly than cocane in compaison. 40-60mg of nicotine is a lethal dose in a human.

and don't forget it works best to put it in their coffee, and a little extra water never hurts when making it.

wow please dont tell me youve tried this

well, not really, but its a known fact that nicotine is poisonous as hell..

Or...

You could get some caffeine tablets and dissolve them in their drink.

I guess you could do that too if you want, I heard something about if you inject someone with 90 cc's of insulin they will die of an apparent heart attack.

Yeah I'm pretty sure that's hollywood legend (it was on Dexter).

why are you guys coming up with ways to kill people

Because you asked that question.

Choke someone to death with a banana they will just think the person was a suicide due to kinky gay banana sucking.