I had a bamboo shrimp once, and if you havent heard of them they use fans to collect their food and always settle down where the most current is. To anchor themselves to the bottom of the tank they have these little hooks on the ends of their legs. Thinking they were community we put them in a 30 gallon with about 5 coreys in it also. After plenty of smashes into the bamboo shrimp by the coreys it finally got pissed enough that it started lashing out and stabbing the the coreys heads.
One corey was impaled right between the eyes. And he lived about another week after that.
One corey was impaled right between the eyes. And he lived about another week after that.